Syringe pump and related method

ABSTRACT

A syringe pump includes a lead screw, a motor, and a sliding block assembly. The lead screw has threads and the motor is coupled to the lead screw to rotate it. The half-nut housing has a half nut and a barrel cam. The half nut is disposed within the half-nut housing. The half nut has half-nut threads at an end adjacent to the lead screw void. The half nut engages or disengages with the threads of the lead screw. The half nut includes a half-nut cam-follower surface and a half nut slot. The barrel cam is disposed within the half-nut housing and engages with the half-nut cam-follower surface. The barrel cam includes a pin to fit within the half nut slot such that the barrel cam rotates between a first position and a second position to actuate the half nut between the engagement position and the disengagement position, respectively.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 13/833,432, filed on Mar. 15, 2013 and entitled“Syringe Pump and Related Method”, now U.S. Publication No.US-2013-0281965-A1, published Oct. 24, 2013 (Attorney Docket No. K21),which claims priority to and the benefit of the following:

U.S. Provisional Patent Application Ser. No. 61/679,117, filed Aug. 3,2012 and entitled System, Method, and Apparatus for Monitoring,Regulating, or Controlling Fluid Flow (Attorney Docket No. J30); and

U.S. Provisional Patent Application Ser. No. 61/651,322, filed May 24,2012 and entitled System, Method, and Apparatus for Electronic PatientCare (Attorney Docket No. J46), both of which are hereby incorporatedherein by reference in their entireties.

U.S. patent application Ser. No. 13/833,432 (Attorney Docket No. K21),claims priority to and is also a Continuation-In-Part application of thefollowing:

U.S. patent application Ser. No. 13/333,574, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care, nowU.S. Publication No. US-2012-0185267-A1, published Jul. 19, 2012(Attorney Docket No. I97), and

PCT Application Serial No. PCT/US11/66588, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care(Attorney Docket No. I97 WO), both of which are hereby incorporatedherein by reference in their entireties.

U.S. patent application Ser. No. 13/833,432 (Attorney Docket No. K21),claims priority to and is also a Continuation-in-Part application ofU.S. patent application Ser. No. 13/723,238, filed Dec. 21, 2012 andentitled System, Method, and Apparatus for Clamping (Attorney Docket No.J47), which claims priority to and the benefit of the following:

U.S. Provisional Patent Application Ser. No. 61/578,649, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Infusing Fluid(Attorney Docket No. J02);

U.S. Provisional Patent Application Ser. No. 61/578,658, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Estimating LiquidDelivery (Attorney Docket No. J04);

U.S. Provisional Patent Application Ser. No. 61/578,674, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Dispensing OralMedications (Attorney Docket No. J05);

U.S. Provisional Patent Application Ser. No. 61/679,117, filed Aug. 3,2012 and entitled System, Method, and Apparatus for Monitoring,Regulating, or Controlling Fluid Flow (Attorney Docket No. J30); and

U.S. Provisional Patent Application Ser. No. 61/651,322, filed May 24,2012 and entitled System, Method, and Apparatus for Electronic PatientCare (Attorney Docket No. J46), each of which is hereby incorporatedherein by reference in its entirety.

U.S. patent application Ser. No. 13/723,238 (Attorney Docket J47) claimspriority to and is a Continuation-In-Part application of the following:

U.S. patent application Ser. No. 13/333,574, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care, nowU.S. Publication No. US-2012-0185267-A1, published Jul. 19, 2012(Attorney Docket No. I97), and

PCT Application Serial No. PCT/US11/66588, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care(Attorney Docket No. I97 WO), both of which are hereby incorporatedherein by reference in their entireties.

U.S. patent application Ser. No. 13/833,432 (Attorney Docket No. K21),claims priority to and is also a Continuation-in-Part application ofU.S. patent application Ser. No. 13/723,235, filed Dec. 21, 2012 andentitled System, Method, and Apparatus for Dispensing Oral Medications(Attorney Docket No. J74), which claims priority to and benefit of thefollowing:

U.S. Provisional Patent Application Ser. No. 61/578,649, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Infusing Fluid(Attorney Docket No. J02);

U.S. Provisional Patent Application Ser. No. 61/578,658, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Estimating LiquidDelivery (Attorney Docket No. J04);

U.S. Provisional Patent Application Ser. No. 61/578,674, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Dispensing OralMedications (Attorney Docket No. J05);

U.S. Provisional Patent Application Ser. No. 61/679,117, filed Aug. 3,2012 and entitled System, Method, and Apparatus for Monitoring,Regulating, or Controlling Fluid Flow (Attorney Docket No. J30); and

U.S. Provisional Patent Application Ser. No. 61/651,322, filed May 24,2012 and entitled System, Method, and Apparatus for Electronic PatientCare (Attorney Docket No. J46), each of which is hereby incorporatedherein by reference in its entirety.

U.S. patent application Ser. No. 13/723,235 claims priority to and is aContinuation-In-Part application of the following:

U.S. patent application Ser. No. 13/333,574, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care, nowU.S. Publication No. US-2012-0185267-A1, published Jul. 19, 2012(Attorney Docket No. I97), and

PCT Application Serial No. PCT/US11/66588, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care(Attorney Docket No. I97 WO), both of which are hereby incorporatedherein by reference in their entireties.

U.S. patent application Ser. No. 13/833,432 (Attorney Docket No. K21),is also a Continuation-In-Part application of PCT Application Serial No.PCT/US12/71131, filed Dec. 21, 2012 and entitled System, Method, andApparatus for Dispensing Oral Medications Attorney Docket No. J74WO),which claims priority to and the benefit of the following:

U.S. Provisional Patent Application Ser. No. 61/578,649, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Infusing Fluid(Attorney Docket No. J02);

U.S. Provisional Patent Application Ser. No. 61/578,658, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Estimating LiquidDelivery (Attorney Docket No. J04);

U.S. Provisional Patent Application Ser. No. 61/578,674, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Dispensing OralMedications (Attorney Docket No. J05);

U.S. Provisional Patent Application Ser. No. 61/651,322, filed May 24,2012 and entitled System, Method, and Apparatus for Electronic PatientCare (Attorney Docket No. J46); and

U.S. Provisional Patent Application Ser. No. 61/679,117, filed Aug. 3,2012 and entitled System, Method, and Apparatus for Monitoring,Regulating, or Controlling Fluid Flow (Attorney Docket No. J30), each ofwhich is hereby incorporated herein by reference in its entirety.

PCT Application Serial No. PCT/US12/71131 claims priority to and is aContinuation-In-Part application of the following:

U.S. patent application Ser. No. 13/333,574, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care, nowU.S. Publication No. US-2012-0185267-A1, published Jul. 19, 2012(Attorney Docket No. I97), and

PCT Application Serial No. PCT/US11/66588, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care(Attorney Docket No. I97 WO), both of which are hereby incorporatedherein by reference in their entireties.

U.S. patent application Ser. No. 13/833,432 (Attorney Docket No. K21),claims priority to and is also a Continuation-In-Part application ofU.S. patent application Ser. No. 13/724,568, filed Dec. 21, 2012 andentitled System, Method, and Apparatus for Estimating Liquid Delivery(Attorney Docket No. J75), which claims priority to and the benefit ofthe following:

U.S. Provisional Patent Application Ser. No. 61/578,649, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Infusing Fluid(Attorney Docket No. J02);

U.S. Provisional Patent Application Ser. No. 61/578,658, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Estimating LiquidDelivery (Attorney Docket No. J04);

U.S. Provisional Patent Application Ser. No. 61/578,674, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Dispensing OralMedications (Attorney Docket No. J05);

U.S. Provisional Patent Application Ser. No. 61/679,117, filed Aug. 3,2012 and entitled System, Method, and Apparatus for Monitoring,Regulating, or Controlling Fluid Flow (Attorney Docket No. J30); and

U.S. Provisional Patent Application Ser. No. 61/651,322, filed May 24,2012 and entitled System, Method, and Apparatus for Electronic PatientCare (Attorney Docket No. J46), each of which is hereby incorporatedherein by reference in its entirety.

U.S. patent application Ser. No. 13/724,568 claims priority to and is aContinuation-In-Part application of the following:

U.S. patent application Ser. No. 13/333,574, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care, nowU.S. Publication No. US-2012-0185267-A1, published Jul. 19, 2012(Attorney Docket No. I97), and

PCT Application Serial No. PCT/US11/66588, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care(Attorney Docket No. I97 WO), both of which are hereby incorporatedherein by reference in their entireties.

U.S. patent application Ser. No. 13/833,432 (Attorney Docket No. K21),claims priority to and is also a Continuation-In-Part application ofU.S. patent application Ser. No. 13/725,790, filed Dec. 21, 2012 andentitled System, Method, and Apparatus for Infusing Fluid (AttorneyDocket No. J76), which claims priority to and the benefit of thefollowing:

U.S. Provisional Patent Application Ser. No. 61/578,649, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Infusing Fluid(Attorney Docket No. J02);

U.S. Provisional Patent Application Ser. No. 61/578,658, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Estimating LiquidDelivery (Attorney Docket No. J04);

U.S. Provisional Patent Application Ser. No. 61/578,674, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Dispensing OralMedications (Attorney Docket No. J05);

U.S. Provisional Patent Application Ser. No. 61/679,117, filed Aug. 3,2012 and entitled System, Method, and Apparatus for Monitoring,Regulating, or Controlling Fluid Flow (Attorney Docket No. J30); and

U.S. Provisional Patent Application Ser. No. 61/651,322, filed May 24,2012 and entitled System, Method, and Apparatus for Electronic PatientCare (Attorney Docket No. J46), each of which is hereby incorporatedherein by reference in its entirety.

U.S. patent application Ser. No. 13/725,790 claims priority to and is aContinuation-In-Part application of the following:

U.S. patent application Ser. No. 13/333,574, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care, nowU.S. Publication No. US-2012-0185267-A1, published Jul. 19, 2012(Attorney Docket No. I97), and

PCT Application Serial No. PCT/US11/66588, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care(Attorney Docket No. I97 WO), both of which are hereby incorporatedherein by reference in their entireties.

U.S. patent application Ser. No. 13/833,432 (Attorney Docket No. K21),is also a Continuation-In-Part application of PCT Application Serial No.PCT/US12/71490, filed Dec. 21, 2012 and entitled System, Method, andApparatus for Infusing Fluid (Attorney Docket No. J76WO), which claimspriority to and the benefit of the following:

U.S. Provisional Patent Application Ser. No. 61/578,649, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Infusing Fluid(Attorney Docket No. J02);

U.S. Provisional Patent Application Ser. No. 61/578,658, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Estimating LiquidDelivery (Attorney Docket No. J04);

U.S. Provisional Patent Application Ser. No. 61/578,674, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Dispensing OralMedications (Attorney Docket No. J05);

U.S. Provisional Patent Application Ser. No. 61/679,117, filed Aug. 3,2012 and entitled System, Method, and Apparatus for Monitoring,Regulating, or Controlling Fluid Flow (Attorney Docket No. J30); and

U.S. Provisional Patent Application Ser. No. 61/651,322, filed May 24,2012 and entitled System, Method, and Apparatus for Electronic PatientCare (Attorney Docket No. J46), each of which is hereby incorporatedherein by reference in its entirety.

PCT Application Serial No. PCT/US12/71490 claims priority to and is aContinuation-In-Part application of the following:

U.S. patent application Ser. No. 13/333,574, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care, nowU.S. Publication No. US-2012-0185267-A1, published Jul. 19, 2012(Attorney Docket No. I97), and PCT Application Serial No.PCT/US11/66588, filed Dec. 21, 2011 and entitled System, Method, andApparatus for Electronic Patient Care (Attorney Docket No. I97 WO), bothof which are hereby incorporated herein by reference in theirentireties.

U.S. patent application Ser. No. 13/833,432 (Attorney Docket No. K21),claims priority to and is also a Continuation-In-Part application ofU.S. patent application Ser. No. 13/723,239, filed Dec. 21, 2012 andentitled System, Method, and Apparatus for Electronic Patient Care(Attorney Docket No. J77), which claims priority to and the benefit ofthe following:

U.S. Provisional Patent Application Ser. No. 61/578,649, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Infusing Fluid(Attorney Docket No. J02);

U.S. Provisional Patent Application Ser. No. 61/578,658, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Estimating LiquidDelivery (Attorney Docket No. J04);

U.S. Provisional Patent Application Ser. No. 61/578,674, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Dispensing OralMedications (Attorney Docket No. J05);

U.S. Provisional Patent Application Ser. No. 61/651,322, filed May 24,2012 and entitled System, Method, and Apparatus for Electronic PatientCare (Attorney Docket No. J46); and

U.S. Provisional Patent Application Ser. No. 61/679,117, filed Aug. 3,2012 and entitled System, Method, and Apparatus for Monitoring,Regulating, or Controlling Fluid Flow (Attorney Docket No. J30), each ofwhich is hereby incorporated herein by reference in its entirety.

U.S. patent application Ser. No. 13/723,239 claims priority to and is aContinuation-In-Part application of the following:

U.S. patent application Ser. No. 13/333,574, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care, nowU.S. Publication No. US-2012-0185267-A1, published Jul. 19, 2012(Attorney Docket No. I97), and

PCT Application Serial No. PCT/US11/66588, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care(Attorney Docket No. I97 WO), both of which are hereby incorporatedherein by reference in their entireties.

U.S. patent application Ser. No. 13/833,432 (Attorney Docket No. K21),claims priority to and is also a Continuation-In-Part application ofU.S. patent application Ser. No. 13/723,242, filed Dec. 21, 2012 andentitled System, Method, and Apparatus for Electronic Patient Care(Attorney Docket No. J78), which claims priority to and the benefit ofthe following:

U.S. Provisional Patent Application Ser. No. 61/651,322, filed May 24,2012 and entitled System, Method, and Apparatus for Electronic PatientCare (Attorney Docket No. J46), which is hereby incorporated herein byreference in its entirety.

U.S. patent application Ser. No. 13/833,432 (Attorney Docket No. K21),claims priority to and is also a Continuation-In-Part application ofU.S. patent application Ser. No. 13/723,244, filed Dec. 21, 2012 andentitled System, Method, and Apparatus for Monitoring, Regulating, orControlling Fluid Flow (Attorney Docket No. J79), which claims priorityto and the benefit of the following:

U.S. Provisional Patent Application Ser. No. 61/578,649, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Infusing Fluid(Attorney Docket No. J02);

U.S. Provisional Patent Application Ser. No. 61/578,658, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Estimating LiquidDelivery (Attorney Docket No. J04);

U.S. Provisional Patent Application Ser. No. 61/578,674, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Dispensing OralMedications (Attorney Docket No. J05);

U.S. Provisional Patent Application Ser. No. 61/651,322, filed May 24,2012 and entitled System, Method, and Apparatus for Electronic PatientCare (Attorney Docket No. J46); and

U.S. Provisional Patent Application Ser. No. 61/679,117, filed Aug. 3,2012 and entitled System, Method, and Apparatus for Monitoring,Regulating, or Controlling Fluid Flow (Attorney Docket No. J30), each ofwhich is hereby incorporated herein by reference in its entirety.

U.S. patent application Ser. No. 13/723,244 claims priority to and is aContinuation-In-Part application of the following:

U.S. patent application Ser. No. 13/333,574, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care, nowU.S. Publication No. US-2012-0185267-A1, published Jul. 19, 2012(Attorney Docket No. I97), and

PCT Application Serial No. PCT/US11/66588, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care(Attorney Docket No. I97 WO), both of which are hereby incorporatedherein by reference in their entireties.

U.S. patent application Ser. No. 13/833,432 (Attorney Docket No. K21),claims priority to and is also a Continuation-In-Part application of PCTApplication Serial No. PCT/US12/71142, filed Dec. 21, 2012 and entitledSystem, Method, and Apparatus for Monitoring, Regulating, or ControllingFluid Flow (Attorney Docket No. J79WO), which claims priority to and thebenefit of the following:

U.S. Provisional Patent Application Ser. No. 61/578,649, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Infusing Fluid(Attorney Docket No. J02);

U.S. Provisional Patent Application Ser. No. 61/578,658, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Estimating LiquidDelivery (Attorney Docket No. J04);

U.S. Provisional Patent Application Ser. No. 61/578,674, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Dispensing OralMedications (Attorney Docket No. J05);

U.S. Provisional Patent Application Ser. No. 61/651,322, filed May 24,2012 and entitled System, Method, and Apparatus for Electronic PatientCare (Attorney Docket No. J46); and

U.S. Provisional Patent Application Ser. No. 61/679,117, filed Aug. 3,2012 and entitled System, Method, and Apparatus for Monitoring,Regulating, or Controlling Fluid Flow (Attorney Docket No. J30), each ofwhich is hereby incorporated herein by reference in its entirety.

PCT Application Serial No. PCT/US12/71142 claims priority to and is aContinuation-In-Part application of the following:

U.S. patent application Ser. No. 13/333,574, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care, nowU.S. Publication No. US-2012-0185267-A1, published Jul. 19, 2012(Attorney Docket No. I97), and

PCT Application Serial No. PCT/US11/66588, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care(Attorney Docket No. I97 WO), both of which are hereby incorporatedherein by reference in their entireties.

U.S. patent application Ser. No. 13/833,432 (Attorney Docket No. K21),claims priority to and is also a Continuation-In-Part application ofU.S. patent application Ser. No. 13/723,251, filed Dec. 21, 2012 andentitled System, Method, and Apparatus for Estimating Liquid Delivery(Attorney Docket No. J81), which claims priority to and the benefit ofthe following:

U.S. Provisional Patent Application Ser. No. 61/578,649, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Infusing Fluid(Attorney Docket No. J02);

U.S. Provisional Patent Application Ser. No. 61/578,658, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Estimating LiquidDelivery (Attorney Docket No. J04);

U.S. Provisional Patent Application Ser. No. 61/578,674, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Dispensing OralMedications (Attorney Docket No. J05);

U.S. Provisional Patent Application Ser. No. 61/651,322, filed May 24,2012 and entitled System, Method, and Apparatus for Electronic PatientCare (Attorney Docket No. J46); and

U.S. Provisional Patent Application Ser. No. 61/679,117, filed Aug. 3,2012 and entitled System, Method, and Apparatus for Monitoring,Regulating, or Controlling Fluid Flow (Attorney Docket No. J30), each ofwhich is hereby incorporated herein by reference in its entirety.

U.S. patent application Ser. No. 13/723,251 claims priority to and is aContinuation-In-Part application of the following:

U.S. patent application Ser. No. 13/333,574, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care, nowU.S. Publication No. US-2012-0185267-A1, published Jul. 19, 2012(Attorney Docket No. I97), and

PCT Application Serial No. PCT/US11/66588, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care(Attorney Docket No. I97 WO), both of which are hereby incorporatedherein by reference in their entireties.

U.S. patent application Ser. No. 13/833,432 (Attorney Docket No. K21),is also a Continuation-In-Part application of PCT Application Serial No.PCT/US12/71112, filed Dec. 21, 2012 and entitled System, Method, andApparatus for Estimating Liquid Delivery (Attorney Docket No. J81WO),which claims priority to and the benefit of the following:

U.S. Provisional Patent Application Ser. No. 61/578,649, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Infusing Fluid(Attorney Docket No. J02);

U.S. Provisional Patent Application Ser. No. 61/578,658, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Estimating LiquidDelivery (Attorney Docket No. J04);

U.S. Provisional Patent Application Ser. No. 61/578,674, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Dispensing OralMedications (Attorney Docket No. J05);

U.S. Provisional Patent Application Ser. No. 61/651,322, filed May 24,2012 and entitled System, Method, and Apparatus for Electronic PatientCare (Attorney Docket No. J46); and

U.S. Provisional Patent Application Ser. No. 61/679,117, filed Aug. 3,2012 and entitled System, Method, and Apparatus for Monitoring,Regulating, or Controlling Fluid Flow (Attorney Docket No. J30), each ofwhich is hereby incorporated herein by reference in its entirety.

PCT Application Serial No. PCT/US12/71112 claims priority to and is aContinuation-In-Part application of the following:

U.S. patent application Ser. No. 13/333,574, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care, nowU.S. Publication No. US-2012-0185267-A1, published Jul. 19, 2012(Attorney Docket No. I97), and

PCT Application Serial No. PCT/US11/66588, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care(Attorney Docket No. I97 WO), both of which are hereby incorporatedherein by reference in their entireties.

U.S. patent application Ser. No. 13/833,432 (Attorney Docket No. K21),claims priority to and is also a Continuation-In-Part application ofU.S. patent application Ser. No. 13/723,253, filed Dec. 21, 2012 andentitled System, Method, and Apparatus for Electronic Patient Care(Attorney Docket No. J85), which claims priority to and the benefit ofthe following:

U.S. Provisional Patent Application Ser. No. 61/578,649, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Infusing Fluid(Attorney Docket No. J02);

U.S. Provisional Patent Application Ser. No. 61/578,658, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Estimating LiquidDelivery (Attorney Docket No. J04);

U.S. Provisional Patent Application Ser. No. 61/578,674, filed Dec. 21,2011 and entitled System, Method, and Apparatus for Dispensing OralMedications (Attorney Docket No. J05);

U.S. Provisional Patent Application Ser. No. 61/651,322, filed May 24,2012 and entitled System, Method, and Apparatus for Electronic PatientCare (Attorney Docket No. J46); and

U.S. Provisional Patent Application Ser. No. 61/679,117, filed Aug. 3,2012 and entitled System, Method, and Apparatus for Monitoring,Regulating, or Controlling Fluid Flow (Attorney Docket No. J30), each ofwhich is hereby incorporated herein by reference in its entirety.

U.S. patent application Ser. No. 13/723,253 claims priority to and is aContinuation-In-Part application of the following:

U.S. patent application Ser. No. 13/333,574, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care, nowU.S. Publication No. US-2012-0185267-A1, published Jul. 19, 2012(Attorney Docket No. I97), and

PCT Application Serial No. PCT/US11/66588, filed Dec. 21, 2011 andentitled System, Method, and Apparatus for Electronic Patient Care(Attorney Docket No. I97 WO), both of which are hereby incorporatedherein by reference in their entireties.

U.S. patent application Ser. No. 13/833,432 (Attorney Docket No. K21),may also be related to one or more of the following U.S. patentapplications filed on Mar. 15, 2013, all of which are herebyincorporated herein by reference in their entireties:

Nonprovisional application for Apparatus for Infusing Fluid (AttorneyDocket No. K14) having the Ser. No. 13/840,339;

PCT Application for Apparatus for Infusing Fluid (Attorney Docket No.K14 WO); Nonprovisional application for System and Apparatus forElectronic Patient Care (Attorney Docket No. K22) having the Ser. No.13/836,497;

Nonprovisional application for System, Method and Apparatus for Clamping(Attorney Docket No. K23) having the Ser. No. 13/833,712; and

Nonprovisional application for System, Method, and Apparatus forMonitoring, Regulating, or Controlling Fluid Flow (Attorney Docket No.K28) having the Ser. No. 13/834,030.

BACKGROUND Relevant Field

The present disclosure relates to pumps. More particularly, the presentdisclosure relates to a system, method, and apparatus for estimatingliquid delivery of a syringe pump.

Description of Related Art

Syringe pumps are used in a variety of medical applications, such as forintravenous delivery of liquid medications, for example a patient in anintensive-care unit (ICU), for an extended length of time. Syringe pumpsmay be designed so that needles, tubing, or other attachments areattachable to the syringe pump. Syringe pumps typically include aplunger mounted to a shaft that pushes a liquid out of a reservoir. Thereservoir may be a tube-shaped structure having a port at one end suchthat the plunger can push (i.e., discharge) the liquid out of thesyringe pump. Syringe pumps can be coupled to an actuator thatmechanically drives the plunger to control the delivery of liquid to thepatient.

Syringe pumps may also be used to deliver various drugs includinganalgesics, antiemetics, or other fluids. The medication may beadministered via an intravenous liquid line very quickly (e.g., in abolus) or over a length of time. Syringe pumps may also be used innon-medical applications, such as in microreactors, in laboratorytesting, and/or in chemical processing applications.

SUMMARY

In accordance with one embodiment of the present disclosure, a pump foradministering an agent to a patient may comprise a housing. Within saidhousing may be a motor, a gearbox operatively connected to said motor, ameans for sensing rotation of said motor, a controller acting to controloperation of said motor and monitor the quantity of said agent deliveredto said patient, and a pump assembly. The pump may be configured suchthat the pump is interchangeable from a syringe pump or peristaltic pumprespectively to a peristaltic pump or syringe pump via supplanting onepump assembly with a differing pump assembly.

In some embodiments, the pump may be field interchangeable from asyringe pump or peristaltic pump respectively to a peristaltic pump orsyringe pump via supplanting one pump assembly with a differing pumpassembly.

In accordance with another embodiment of the present disclosure, asyringe pump for administering an agent to a patient may comprise ahousing, a lead screw, and a sliding block assembly. The sliding blockassembly may comprise a cam, a cam projection fixedly coupled to thecam, and a threaded portion capable of engaging and disengaging from thelead screw. The threaded portion may be configured to be actuatedbetween engagement and disengagement on the lead screw via rotation ofthe cam and cam projection.

In some embodiments, the sliding block assembly may comprise a slot witha straight expanse and an acruated expanse.

In some embodiments, rotation of the cam may cause the cam projection tomove within the slot. As the cam projection moves within the straightexpanse of the slot, the threaded portion may be configured to beactuated between engagement and disengagement with the lead screw.

In some embodiments, the syringe pump may further comprise a clampingmeans configured for clamping any of a range of plunger flange sizes.

In some embodiments, the cam projection may not enter the straightexpanse of the slot until the largest of the range of plunger flangesizes has been released by the means configured for clamping any of arange of plunger flange sizes.

In some embodiments, the syringe pump may further comprise a plungerhead assembly coupled to the sliding block and operative to drive aplunger of a syringe into a barrel of the syringe. A plunger tube maycouple the plunger head assembly to the sliding block.

In some embodiments, the plunger tube may perform at least one or moreadditional functions from a list consisting of: a bushing support for atleast one rotating shaft, a channel for electrical conduits to and fromthe plunger head assembly, and a channel for data transmission conduitsto and from the plunger head assembly.

In some embodiments, the syringe pump may further comprise a barrelflange clip configured to retain a barrel flange of a syringe.

In some embodiments, the barrel flange clip may comprise a means ofdetecting the presence of a barrel flange. The means of detecting thepresence of a barrel flange may comprise an optical sensor and a lightsource. The light source may be obscured in the presence of the barrelflange.

In some embodiments, the location of the cam of the sliding blockassembly may be adjustable such that a user may optimize engagement ofthe threaded portion on the lead screw.

In some embodiments, the sliding block assembly may further include atleast one bias member. The bias member may be configured to bias thethreaded portion to one of an engaged position on the lead screw and adisengaged position on the lead screw.

In accordance with another aspect of the present disclosure, a syringepump for administering an agent to a patient may comprise a housing, alead screw, and a sliding block assembly. The sliding block assembly maycomprise a threaded section configured for engaging and disengaging fromthe lead screw. The syringe pump may further comprise a plunger headassembly coupled to said sliding block and operative to drive a plungerof a syringe into a barrel of said syringe. The syringe pump may furthercomprise a clamping means configured for clamping any of a range ofplunger flange sizes. The means configured for clamping any of a rangeof plunger flange sizes may comprise at least a first plunger flangeclamp jaw and a second plunger flange clamp jaw. The first and secondplunger flange clamp jaws may be configured to be actuated from a firstposition to a position in which at least one point of each of the firstand second plunger flange clamp jaws abut an edge of the plunger flangeforcing the plunger flange against the plunger head assembly and actingas an anti-siphon mechanism.

In some embodiments, the means configured for clamping any of a range ofplunger flange sizes may comprise a cam, at least one cam follower, andat least one bias member. The bias member may bias said means configuredfor clamping any of a range of plunger flange sizes toward a firstposition. In some embodiments, movement of the at least one cam followeralong the cam may overcome the bias member and allow the meansconfigured for clamping any of a range of plunger flange sizes to movetoward a second position.

In some embodiments, the cam, at least one cam follower, and at leastone bias member may be coupled to a rotatable shaft. The cam may not berotatable with said shaft but may be displaceable along an axialdimension of said shaft. The at least one cam follower may be fixedlycoupled to the shaft and rotatable with the shaft. Rotation of the shaftmay cause movement of the at least one cam follower along the camthereby displacing the cam along the axial dimension of the shaft.

In some embodiments, the bias member may automatically return the meansconfigured for clamping any range of plunger flange sizes to the firstposition in the absence of a force sufficient to overcome the biasmember.

In some embodiments, the cam may comprise at least one detent, each ofsaid detents being reached by one of the at least one cam followers whenthe means configured for clamping any range of plunger flange sizes hasbeen allowed to move to the second position.

In some embodiments, the plunger head assembly may further comprise apressure sensor for monitoring the pressure of the agent being dispensedfrom the syringe.

In some embodiments, the plunger flange of the syringe may be heldagainst the pressure sensor by the means configured for clamping anyrange of plunger flange sizes.

In some embodiments, the syringe pump may further comprise a barrelflange clip. The barrel flange clip may be configured to retain a barrelflange of the syringe.

In some embodiments, the barrel flange clip may comprise a means ofdetecting the presence of a barrel flange. The means of detecting thepresence of a barrel flange may comprise an optical sensor and a lightsource. The light source may be obscured in the presence of said barrelflange.

In accordance with another aspect of the present disclosure a syringepump for administering an agent to a patient may comprise a housing alead screw and a sliding block assembly. The sliding block assembly maycomprise a threaded section configured for engagement and disengagementwith said lead screw and movable along said lead screw. The syringe pumpmay further comprise a plunger head assembly coupled to said slidingblock assembly and operative to drive a plunger of a syringe into abarrel of said syringe. The syringe pump may further comprise a clampingmeans configured for clamping any of a range of plunger flange sizes.The syringe pump may further comprise a means of monitoring the clampingmeans. The means of monitoring the clamping means may be capable ofgenerating data to determine at least one characteristic of the clampedsyringe.

In some embodiments, the means of monitoring the clamping means may be apotentiometer.

In some embodiments, the data generated by the means of monitoring theclamping means may be evaluated by referencing said data against adatabase.

In some embodiments, the data generated by the means of monitoring theclamping means may be evaluated by referencing said data against adatabase and data generated by at least one other sensor.

In some embodiments, the clamping means may comprise a cam, at least onecam follower, and at least one bias member. The bias member may biassaid clamping means toward a first position. Movement of the at leastone cam follower along the cam may overcome the bias member and allowthe clamping means to move toward a second position.

In some embodiments, the cam, at least one cam follower, and at leastone bias member may be coupled to a rotatable shaft. In some specificembodiments, the cam may not be rotatable with the shaft but may bedisplaceable along an axial dimension of said shaft. The at least onecam follower may be fixedly coupled to the shaft and rotatable with theshaft. Rotation of the shaft may cause movement of the at least one camfollower along the cam displacing the cam along the axial dimension ofthe shaft.

In some embodiments, the bias member may automatically return theclamping means to the first position in the absence of a forcesufficient to overcome the bias member.

In some embodiments, the cam may comprise at least one detent. Each ofthe detents may be reached by one of the at least one cam followers whenthe means for clamping any range of plunger flange sizes has beenallowed to move to the second position.

In some embodiments, the plunger head assembly may further comprise apressure sensor for monitoring the pressure of the agent being dispensedfrom the syringe.

In some embodiments, a plunger flange of the syringe may be held againstthe pressure sensor by the clamping means.

In some embodiments, the barrel flange clip may comprise a means ofdetecting the presence of a barrel flange. The means of detecting thepresence of said barrel flange may comprise an optical sensor and alight source. The light source may be obscured in the presence of saidbarrel flange.

In accordance with another aspect of the present disclosure, a syringepump for administering an agent to a patient may comprise a housing, alead screw, and a plunger head assembly operatively coupled to drive aplunger of a syringe into the barrel of a syringe with rotation of saidlead screw. The syringe pump may further comprise at least one set ofredundant sensors. The redundant sensors may be configured such that ifpart of a set of redundant sensors is compromised, the syringe pump mayfunction in a fail operative mode for at least the duration of atherapy. One or more of the set of redundant sensors are configured tomonitor the volume being infused.

In accordance with another aspect of the present disclosure, a syringepump for administering an agent to a patient may comprise a housing anda syringe barrel holder which may be movable between a first positionand a second position. The syringe barrel holder may be biased by a biasmember to either the first position or the second position. The syringepump may further comprise a syringe barrel contacting member. The barrelcontacting member may be coupled to said syringe barrel holder andconfigured to hold the syringe in place on the housing. The syringe pumpmay further comprise a detector capable of sensing the position of thesyringe barrel holder and generating position data based on the positionof the syringe barrel holder. When a syringe is in place on saidhousing, the syringe barrel holder may be biased such that the syringeis held in place on said housing. The position data generated by saiddetector may be indicative of at least one characteristic of the syringeand evaluated to determine said characteristic.

In some embodiments the detector may be a linear potentiometer.

In some embodiments, the detector may be a magnetic linear positionsensor.

In some embodiments, the syringe barrel holder may be configured to belocked in at least one of the first position and second position.

In some embodiments, the bias member may cause the syringe barrel holderto automatically adjust to the size of the syringe.

In some embodiments, position data generated by the detector may bereferenced against a database to determine the at least onecharacteristic of the syringe.

In some embodiments, the position data generated by the detector may bereferenced against a database and data from at least one other sensor todetermine the at least one characteristic of the syringe.

In accordance with another aspect of the present disclosure, a method ofadministering an agent to a patient via a syringe pump may comprisedefining one or a number of parameters for an infusion through aninterface of the syringe pump. The method may further comprisereferencing said parameters against a medical database and placingrestrictions on further parameters to be defined through the interfaceof the syringe pump. One of the further parameters may be an end ofinfusion behavior to be executed by the syringe pump after a volume tobe infused has been infused. The method may further comprise infusingsaid agent to said patient in accordance with the defined parameters forinfusion and executing the specified end of infusion behavior.

In some embodiments, the end of infusion behavior may be selected from alist consisting of: stopping an infusion, infusing at a keep vein openrate, and continuing to infuse at the rate of the finished infusion.

In some embodiments, referencing parameters against a database andplacing restrictions on further parameters may comprise referencing theagent against the database.

In accordance with one embodiment of the present disclosure, a syringepump includes a housing, a syringe seat, and a bumper. The syringe seatis coupled to the housing. The bumper is coupled to the housing adjacentto the syringe seat. The bumper may at least partially surround a cornerof the syringe seat.

In another embodiment of the present disclosure, a syringe pump includesa housing, a syringe seat, and a power supply. The syringe seat iscoupled to the housing. The power supply is coupled to the housing suchthat the housing is configured as a heat sink for the power supply. Thesyringe pump may include a motor, and the motor may be coupled to thehousing such that the housing is a heat sink for the motor. The housingmay be die casted. The housing may comprise at least one metal and/ormay be a unitary body.

In another embodiment of the present disclosure, a syringe pump includesa user interface, an antenna, and a split-ring resonator. The userinterface has a front side and a backside. The antenna is disposed onthe back side of the user interface. The split-ring resonator isdisposed in spaced relation to the user interface and is configured tooperate with the antenna.

The user interface may include a touchscreen sensor. The split-ringresonator may be disposed on a backside of the touchscreen sensor. Aframe may surround the touchscreen sensor that has a gap such that theframe defines the split-ring resonator. A dielectric may be disposedwithin the gap.

In another embodiment of the present disclosure, a syringe pump includesa housing, a lead screw, a motor, a rotary position sensor, a slidingblock assembly, a linear position sensor, and one or more processors.The lead screw is rotatable within the housing. The motor is operativelycoupled to the lead screw and is configured to rotate the lead screw.The motor has an integral motor rotation sensor configured to provide amotor rotation signal. The rotary position sensor is operatively coupledto the motor or the lead screw to provide a rotation signal. The rotaryposition sensor may be a magnetic encoder sensor. The sliding blockassembly is configured to engage with the lead screw to actuate thesliding block assembly along the lead screw in accordance with rotationof the lead screw. The linear position sensor is operatively coupled tothe sliding block assembly and is configured to provide a linearposition signal. The one or more processors are configured to controlrotation of the motor. The one or more processors operatively receivethe motor rotation signal from the integral motor rotation sensor of themotor, the rotation signal from the rotary position sensor, and thelinear position signal from the linear position sensor. The one or moreprocessors are configured to determine if a discrepancy exists among themotor rotation signal, the rotation signal, and the linear positionsignal. The one or more processors may be further configured to continuean infusion treatment by ignoring an inoperative one of the integralmotor rotation sensor, the rotary position sensor, and a linear positionsensor.

In another embodiment of the present disclosure, a syringe pump includesa housing, a lead screw, a sliding block assembly, a plunger, and firstand second pivotal jaw members. The lead screw is rotatable within thehousing. The sliding block assembly is configured for engaging with thelead screw to move along the lead screw in accordance with rotation ofthe lead screw. The plunger head assembly is coupled to the slidingblock assembly and is configured to drive a plunger of a syringe into abarrel of the syringe. The first and second pivotal jaw members are eachpivotally coupled to the plunger head assembly. The first and secondpivotal jaw members are configured to pivot toward each other to retaina plunger flange of the syringe. The first pivotal jaw member and/or thesecond pivotal jaw member includes a bend.

The syringe pump may further include a knob coupled to the sliding blockassembly. The knob may be operatively coupled to the first and secondpivotal jaw members to pivotally actuate the first and second pivotaljaw members. The pump may include a bias member configured to bias theknob in a direction of rotation. The bias member may be configured toautomatically return the first and second pivotal jaw members to aposition away from each other. The bias member may be configured toautomatically return the first and second pivotal jaw members to aposition toward each other.

In another embodiment, a syringe pump includes a housing, a syringe seatcoupled to the housing, and a retaining finger. The retaining finger ispivotally coupled to the housing and is configured to rotate toward asyringe disposed within the syringe seat to retain the syringe.

In another embodiment of the present disclosure, a method is providedfor removing the effects of slack in a syringe pump having a syringeloaded on the syringe pump. The syringe has a barrel and a plungerdisposed within the barrel. The method includes the acts of: receiving atarget flow rate of the syringe loaded on the syringe pump; determininga therapy actuation speed corresponding to the target flow rate;actuating the plunger of the syringe out of the barrel at a firstpredetermined speed until a force sensor coupled to the plunger measuresa force that is less than a first predetermined force threshold;actuating the plunger of the syringe into the barrel at a secondpredetermined speed greater than the therapy actuation speed until theforce sensor coupled to the plunger measures a force that exceeds asecond predetermined threshold; and actuating the plunger of the syringeinto the barrel at the therapy actuation speed. The therapy actuationspeed may correspond to the target flow rate when there is no slack inthe syringe pump or the syringe. The method may further include the actsof: estimating a volume discharged starting from the position of theplunger when the second predetermined threshold was exceeded; and/orstopping the syringe pump when the estimated volume discharged is equalto or exceeds a target delivery volume.

In another embodiment of the present disclosure, a method is providedfor removing the effects of slack in a syringe pump having a syringeloaded on the syringe pump. The syringe has a barrel and a plungerdisposed within the barrel. The method includes the acts of: receiving atarget flow rate of the syringe loaded on the syringe pump; determininga therapy actuation speed corresponding to the target flow rate;actuating the plunger of the syringe out of the barrel at a firstpredetermined speed until a force sensor coupled to the plunger measuresa force that is less than a first predetermined force threshold or theplunger travels out of the barrel by a first predetermined distance;actuating the plunger of the syringe into the barrel at a secondpredetermined speed greater than the therapy actuation speed until theforce sensor coupled to the plunger measures a force that exceeds asecond predetermined threshold or the plunger travels into the barrel bya second predetermined distance; and actuating the plunger of thesyringe into the barrel at the therapy actuation speed.

The therapy actuation speed may correspond to the target flow rate whenthere is no slack in the syringe pump or the syringe. The method mayfurther include the acts of: estimating a volume discharged startingfrom the position of the plunger when the second predetermined thresholdwas exceeded; stopping the syringe pump when the estimated volumedischarged is equal to or exceeds a target delivery volume; and/or usingan alarm if the plunger traveled into the barrel by the secondpredetermined distance without the force sensor measuring a force thatexceeds the second predetermined threshold.

In another embodiment of the present disclosure, a syringe pump includesa housing, a syringe seat, a lead screw, a motor, a sliding blockassembly, a plunger head assembly, and one or more processors. Thesyringe seat is coupled to the housing and is configured to retain asyringe having a barrel and a plunger disposed within the barrel. Thelead screw is rotatable within the housing. The motor is coupled to thelead screw and is configured rotate the lead screw. The sliding blockassembly may be configured for engaging with the lead screw to movealong the lead screw in accordance with rotation of the lead screw. Theplunger head assembly is coupled to the sliding block assembly and isconfigured to drive a plunger of a syringe into a barrel of the syringe.The plunger head assembly has a force sensor operatively coupled to theplunger of the syringe to measure a force of the plunger head assemblyon the plunger of the syringe. The one or more processors areoperatively coupled to the motor and are configured to control therotation of the motor to thereby control actuation of the plunger headassembly. The one or more processors are also operatively coupled to theforce sensor to receive a measured force therefrom and are configuredto: receive a target flow rate of the syringe loaded on the syringepump; determine a therapy actuation speed corresponding to the targetflow rate; command the motor to actuate the plunger of the syringe outof the barrel at a first predetermined speed until the force sensorcoupled to the plunger measures a force that is less than a firstpredetermined force threshold; command the motor to actuate the plungerof the syringe into the barrel at a second predetermined speed greaterthan the therapy actuation speed until the force sensor coupled to theplunger measures a force that exceeds a second predetermined threshold;and command the motor to actuate the plunger of the syringe into thebarrel at the therapy actuation speed. The therapy actuation speed maycorrespond to the target flow rate when there is no slack in the syringepump or the syringe.

The one or more processors may be configured to estimate a volumedischarged starting from the position of the plunger when the secondpredetermined threshold was exceeded.

The one or more processors may be further configured to stop the syringepump when the estimated volume discharged is equal to or exceeds atarget delivery volume.

In yet another embodiment of the present disclosure, a syringe pumpincludes a housing, a syringe seat, a lead screw, a motor, a slidingblock assembly, a plunger head assembly, and one or more processors. Thesyringe seat is coupled to the housing and is configured to retain asyringe having a barrel and a plunger disposed within the barrel. Thelead screw is rotatable within the housing. The motor is coupled to thelead screw and is configured rotate the lead screw. The sliding blockassembly may be configured for engaging with the lead screw to movealong the lead screw in accordance with rotation of the lead screw. Theplunger head assembly is coupled to the sliding block assembly and isconfigured to drive a plunger of a syringe into a barrel of the syringe.The plunger head assembly has a force sensor operatively coupled to theplunger of the syringe to measure a force of the plunger head assemblyon the plunger of the syringe. The one or more processors areoperatively coupled to the motor and are configured to control therotation of the motor to thereby control actuation of the plunger headassembly. The one or more processors are also operatively coupled to theforce sensor to receive a measured force therefrom and are configuredto: receive a target flow rate of the syringe loaded on the syringepump; determine a therapy actuation speed corresponding to the targetflow rate; command the motor to actuate the plunger of the syringe outof the barrel at a first predetermined speed until a force sensorcoupled to the plunger measures a force that is less than a firstpredetermined force threshold or the plunger travels out of the barrelby a first predetermined distance; command the motor to actuate theplunger of the syringe into the barrel at a second predetermined speedgreater than the therapy actuation speed until the force sensor coupledto the plunger measures a force that exceeds a second predeterminedthreshold or the plunger travels into the barrel by a secondpredetermined distance; and command the motor to actuate the plunger ofthe syringe into the barrel at the therapy actuation speed. The therapyactuation speed may correspond to the target flow rate when there is noslack in the syringe pump or the syringe.

The one or more processors may be further configured to estimate avolume discharged starting from the position of the plunger when thesecond predetermined threshold was exceeded and/or to stop the syringepump when the estimated volume discharged is equal to or exceeds atarget delivery volume

The one or more processors may be further configured to issue an alarmif the plunger traveled into the barrel by the second predetermineddistance without the force sensor measuring a force that exceeds thesecond predetermined threshold.

The syringe pump described herein may further comprise a transceiver,and the one or more processors are configured to communicate via thetransceiver with a monitoring client.

In some embodiments, the syringe pump includes a Patient-controlledanalgesia (“PCA”) button to deliver at least one pain medication.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects will become more apparent from the followingdetailed description of the various embodiments of the presentdisclosure with reference to the drawings wherein:

FIG. 1 is a illustration of an electronic patient-care system having asyringe pump in accordance with an embodiment of the present disclosure;

FIGS. 2-5 show several views of a patient bedside system in accordancewith an embodiment of the present disclosure;

FIG. 6 shows a close-up view of a portion of an interface of a clampthat is attachable to a pump shown in FIGS. 2-5 in accordance with anembodiment of the present disclosure;

FIG. 7 shows another close-up view of another portion of the interfaceshown in FIG. 6 in accordance with an embodiment of the presentdisclosure;

FIG. 8 shows a perspective view of a pump attachable to the patientbedside system of FIGS. 2-5 in accordance with an embodiment of thepresent disclosure;

FIG. 9 shows a perspective view of a pump shown in FIGS. 2-5 inaccordance with an embodiment of the present disclosure;

FIGS. 10-13 show several views of a syringe pump in accordance with anembodiment of the present disclosure;

FIG. 14 shows several of the syringe pump of FIGS. 10-13 mounted on apole in accordance with an embodiment of the present disclosure;

FIGS. 15-16 illustrate portions of the operation of the syringe pump ofFIGS. 10-13 in accordance with an embodiment of the present disclosure;

FIGS. 17-18 illustrate several medical devices mounted on a pole inaccordance with an embodiment of the present disclosure;

FIGS. 19-22 show several views of a medical device of FIGS. 17-18 inaccordance with an embodiment of the present disclosure;

FIG. 23 shows several mounts mounted on a pole in accordance with anembodiment of the present disclosure;

FIGS. 24-26 show several views of a mount of FIG. 23 in accordance withan embodiment of the present disclosure;

FIG. 27 shows a circuit diagram having a speaker and battery inaccordance with an embodiment of the present disclosure;

FIG. 28 shows a view of an exemplary embodiment of a syringe pump inaccordance with an embodiment of the present disclosure;

FIG. 29 shows a front view of an exemplary embodiment of a syringe pumpin accordance with an embodiment of the present disclosure;

FIG. 30 is a view of an exemplary embodiment of the syringe pumpassembly in accordance with an embodiment of the present disclosure;

FIG. 31 is another view of an exemplary embodiment of the syringe pumpassembly in accordance with an embodiment of the present disclosure;

FIG. 32 is another view of an exemplary embodiment of the syringe pumpassembly in accordance with an embodiment of the present disclosure;

FIG. 33 is another view of an exemplary embodiment of the syringe pumpassembly in accordance with an embodiment of the present disclosure;

FIG. 34 is another view of an exemplary embodiment of the syringe pumpassembly in accordance with an embodiment of the present disclosure;

FIG. 35 is a view of an exemplary embodiment of the plunger headassembly, plunger tube, and sliding block assembly of the syringe pumpassembly in accordance with an embodiment of the present disclosure;

FIG. 36 is another view of an exemplary embodiment of the plunger headassembly, plunger tube, and sliding block assembly of the syringe pumpassembly in accordance with an embodiment of the present disclosure;

FIG. 37 is an exploded view of an exemplary embodiment of the top of theplunger head assembly with half of the plunger head assembly removed inaccordance with an embodiment of the present disclosure;

FIG. 38 is an assembled view of an exemplary embodiment of the top ofthe plunger head assembly with half of the plunger head assembly removedin accordance with an embodiment of the present disclosure;

FIG. 39 is a bottom view of an exemplary embodiment of the top of theplunger head assembly in accordance with an embodiment of the presentdisclosure;

FIG. 40 is an assembled top view of an exemplary embodiment of thebottom of the plunger head assembly and plunger tube in accordance withan embodiment of the present disclosure;

FIG. 41 is an exploded view of an exemplary embodiment of the dial shaftand related parts of the syringe pump in accordance with an embodimentof the present disclosure;

FIG. 42 is an assembled view of the exemplary embodiment of FIG. 41 inaccordance with an embodiment of the present disclosure;

FIG. 43 is a partially assembled view of an exemplary embodiment of theplunger head assembly and plunger tube in accordance with an embodimentof the present disclosure;

FIG. 44 is a view of an exemplary embodiment of the plunger headassembly with the plunger head assembly housing top removed inaccordance with an embodiment of the present disclosure;

FIG. 45 is a top view of the exemplary embodiment of FIG. 44 inaccordance with an embodiment of the present disclosure;

FIG. 46 is a partial view of an exemplary embodiment of the plunger headassembly in which the D-shaped connector is shown in cross section inaccordance with an embodiment of the present disclosure;

FIG. 47 is a view of an exemplary embodiment of the plunger headassembly, plunger tube, and sliding block assembly in which the slidingblock assembly is exploded in accordance with an embodiment of thepresent disclosure;

FIG. 48A is an exploded view of an exemplary embodiment of the slidingblock assembly in accordance with an embodiment of the presentdisclosure;

FIG. 48B is a view an exemplary embodiment of the lead screw, half nut,barrel cam, and drive shaft in accordance with an embodiment of thepresent disclosure;

FIG. 49 is a partial front view of an exemplary embodiment of the halfnut and barrel cam in which the half nut is shown as transparent inaccordance with an embodiment of the present disclosure;

FIG. 50 is a front view of an exemplary embodiment of the sliding blockassembly in which the half nut is in an engaged position in accordancewith an embodiment of the present disclosure;

FIG. 51 is a front view of an exemplary embodiment of the sliding blockassembly in which the half nut is in the engaged position in accordancewith an embodiment of the present disclosure;

FIG. 52 is a front view of an exemplary embodiment of the sliding blockassembly in which the half nut is in the disengaged position inaccordance with an embodiment of the present disclosure;

FIG. 53 is a cross sectional view of an exemplary embodiment of thesliding block assembly on the lead screw and guide rod in accordancewith an embodiment of the present disclosure;

FIG. 54 is a view of an exemplary embodiment of the rear face of thesyringe pump assembly in accordance with an embodiment of the presentdisclosure;

FIG. 55 is another view of an exemplary embodiment of the rear face ofthe syringe pump assembly with the gearbox in place in accordance withan embodiment of the present disclosure;

FIG. 56 is an interior view of an exemplary embodiment of the syringepump assembly in accordance with an embodiment of the presentdisclosure;

FIG. 57 is another interior view of an exemplary embodiment of thesyringe pump assembly with the sliding block assembly and linearposition sensors in place in accordance with an embodiment of thepresent disclosure;

FIG. 57A is a top view of an embodiment of a magnetic linear positionsensor in accordance with an embodiment of the present disclosure;

FIG. 58 is a partially assembled front view of an exemplary embodimentof the sliding block assembly, plunger tube, and plunger head assemblyin accordance with an embodiment of the present disclosure;

FIG. 59A is a view of an exemplary embodiment of the syringe pumpassembly in accordance with an embodiment of the present disclosure;

FIGS. 59B-59J are electrical schematics of the syringe pump inaccordance with an embodiment of the present disclosure;

FIG. 60 is a bottom partial view of an exemplary embodiment of thesyringe pump assembly in accordance with an embodiment of the presentdisclosure;

FIG. 61 is a partial view of an exemplary embodiment of the syringe pumpassembly in which a barrel flange of a small syringe has been clipped bythe barrel flange clip in accordance with an embodiment of the presentdisclosure;

FIG. 62 is a partial view of an exemplary embodiment of the syringe pumpassembly in which a barrel flange of a large syringe has been clipped bythe barrel flange clip in accordance with an embodiment of the presentdisclosure;

FIG. 63 is a view of an exemplary embodiment of the syringe barrelholder in accordance with an embodiment of the present disclosure;

FIG. 64 is a partial view of an exemplary embodiment of the syringebarrel holder in accordance with an embodiment of the presentdisclosure;

FIG. 65 is a view of an exemplary embodiment of the syringe barrelholder in which the syringe barrel holder is locked in the fully openposition in accordance with an embodiment of the present disclosure;

FIG. 66 is a view of an exemplary embodiment the syringe barrel holderlinear position sensor in which the linear position sensor printedcircuit board is shown as transparent in accordance with an embodimentof the present disclosure;

FIG. 67 is a view of an exemplary embodiment of a phase change detectorlinear position sensor in accordance with an embodiment of the presentdisclosure;

FIG. 68 shows a schematic of the exemplary view of a phase changedetector linear position sensor in accordance with an embodiment of thepresent disclosure;

FIG. 69 shows a schematic of the exemplary view of a phase changedetector linear position sensor in accordance with an embodiment of thepresent disclosure;

FIG. 70 shows a schematic of the exemplary view of a phase changedetector linear position sensor in accordance with an embodiment of thepresent disclosure;

FIG. 71 shows a perspective view of a pump with the graphic userinterface shown on the screen in accordance with an embodiment of thepresent disclosure;

FIG. 72 shows an example infusion programming screen of the graphic userinterface in accordance with an embodiment of the present disclosure;

FIG. 73 shows an example infusion programming screen of the graphic userinterface in accordance with an embodiment of the present disclosure;

FIG. 74 shows an example infusion programming screen of the graphic userinterface in accordance with an embodiment of the present disclosure;

FIG. 75 shows an example infusion programming screen of the graphic userinterface in accordance with an embodiment of the present disclosure;

FIG. 76 shows an example infusion programming screen of the graphic userinterface in accordance with an embodiment of the present disclosure;

FIG. 77 shows an infusion rate over time graphical representation of anexample infusion in accordance with an embodiment of the presentdisclosure;

FIG. 78 shows an infusion rate over time graphical representation of anexample infusion in accordance with an embodiment of the presentdisclosure;

FIG. 79 shows an infusion rate over time graphical representation of anexample infusion in accordance with an embodiment of the presentdisclosure;

FIG. 80 shows an infusion rate over time graphical representation of anexample infusion in accordance with an embodiment of the presentdisclosure;

FIG. 81 shows an infusion rate over time graphical representation of anexample infusion in accordance with an embodiment of the presentdisclosure;

FIG. 82 shows an example drug administration library screen of thegraphic user interface in accordance with an embodiment of the presentdisclosure;

FIG. 83 shows a block software diagram in accordance with an embodimentof the present disclosure;

FIG. 84 shows a state diagram illustrating a method of providing awatchdog functionality in accordance with an embodiment of the presentdisclosure;

FIGS. 85A-85F show a circuit diagram of a watchdog system that is oneembodiment that implements the watchdog functionality of the statediagram of FIG. 84 in accordance with another embodiment of the presentdisclosure;

FIG. 86 shows another embodiment of syringe pump having a bumper inaccordance with an embodiment of the present disclosure;

FIG. 87 shows an exploded view of the syringe pump of FIG. 86 inaccordance with an embodiment of the present disclosure;

FIG. 88 shows a close-up view of the upper housing, the lower housing,and the power supply of the syringe pump of FIG. 86 in accordance withan embodiment of the present disclosure;

FIG. 89A shows a front view of the display of the pump of FIG. 86 inaccordance with an embodiment of the present disclosure;

FIG. 89B shows a back view of the display of the pump of FIG. 86 inaccordance with an embodiment of the present disclosure;

FIG. 90 shows the back of the sensor portion of the touchscreen and aframe-based split-ring resonator of for use with a near-field antenna inaccordance with an embodiment of the present disclosure;

FIG. 91 shows a diagram illustrating the use of the sensors of the pumpof FIG. 86 when one or more of the sensors are unavailable in accordancewith an embodiment of the present disclosure;

FIG. 92 shows a side view of a syringe pump having a retaining finger toretain a syringe in accordance with an embodiment of the presentdisclosure;

FIG. 93 shows a close-up view of the syringe pump of FIG. 92 inaccordance with an embodiment of the present disclosure;

FIG. 94 shows a circuit for storing data within an RFID tag associatedwith a syringe pump in accordance with an embodiment of the presentdisclosure;

FIG. 95 shows an equivalent circuit for impedance as seen from the RFIDtag of FIG. 94 in accordance with an embodiment of the presentdisclosure;

FIG. 96 shows another circuit for storing data within an RFID tagassociated with a syringe pump in accordance with an embodiment of thepresent disclosure;

FIG. 97 shows a split-ring resonator used with the circuit of FIG. 96 inaccordance with an embodiment of the present disclosure; and

FIG. 98 shows a flow chart diagram illustrating a method for removingthe effects of slack in a syringe pump having a syringe loaded on thesyringe pump in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

FIG. 1 shows an exemplary arrangement of a system 1 for electronicpatient care in accordance with an embodiment of the present disclosure.The system 1 includes a monitoring client 2 that is linked to a numberof patient-care devices via docks 3 and 11, including an infusion pump 4connected to and delivering from a smaller bag of liquid 5, an infusionpump 6 connected to and delivering from a larger bag of liquid 7, a dripdetection device 8 connected to tubing from the smaller bag 5, and amicroinfusion pump 9. System 1 also includes a syringe pump 10 connectedwirelessly to the monitoring client 2. In some embodiments, themonitoring client 2 may communicate with these patient-care devices in awired fashion, as shown in FIG. 1 for the infusion pumps 4 and 6, andthe microinfusion pump 9 (via docks 3 and 11). Additionally oralternatively, the monitoring client 2 may communicate wirelessly withpatient-care devices, as suggested by the absence of a wired connectionbetween the syringe pump 10 and the monitoring client 2.

In some embodiments, a wired connection between the monitoring client 2and a patient-care device also affords an opportunity for electricalpower to be supplied to the patient-care device from the monitoringclient 2. In this exemplary embodiment, the monitoring client 2 mayinclude the electronic circuitry necessary to convert the voltage topower the patient-care device from either a battery attached to themonitoring client 2 or from an Alternative Current (“AC”) line voltagefed into the monitoring client 2 from a power outlet (not shown) in apatient's room. Additionally or alternatively, the dock 3 supplies powerto the infusion pumps 4 and 6, and to the microinfusion pump 9, e.g.,from a signal generated from an AC line voltage.

In an embodiment, the monitoring client 2 is capable of receivinginformation about each patient-care device with which it is linkedeither directly from the device itself, or via a docking station, suchas, for example, the dock 3 onto which the patient-care device may bemounted. The dock 3 may be configured to receive one or morepatient-care devices via a standardized connection mount, or in somecases via a connection mount individualized for the particular device.For example, infusion pumps 4 and 6 may be mounted to the dock 3 via asimilar connection mount, whereas the microinfusion pump 9, for example,may be mounted to the dock 3 via a connection mount configured for theparticular dimensions of the microinfusion pump's 9 housing.

The dock 3 may be configured to electronically identify the particularpatient-care device being mounted on the docking station, and totransmit this identifying information to the monitoring client 2, eitherwirelessly or via a wired connection. Additionally or alternatively,wireless patient-care devices may transmit the identifying informationwirelessly to the monitoring client 2, e.g., during a discoveryprotocol. Additionally, the particular patient-care device may bepreprogrammed with treatment information (e.g., patient-treatmentparameters such as an infusion rate for a predetermined infusion liquid)that is transmitted to the monitoring client 2. For example, the syringepump 10 may include identity information and treatment information, suchas what medication has been prescribed to the patient, what liquid iswithin the syringe pump's 10 reservoir, how much and how long the liquidis prescribed to be delivered to the patient, who are the authorizedcaregivers, etc. In some embodiments of the present disclosure, themonitoring client 2 communicates with EMR records to verify that thepreprogrammed treatment information is safe for an identified patientand/or the preprogrammed treatment information matches the prescribedtreatment stored in the EMR records.

In some embodiments, the drip detection device 8 may communicate withthe monitoring client 2 either wirelessly or in a wired connection. Ifan aberrant liquid flow condition is detected (e.g., because the tubingto the patient has become occluded), a signal may be transmitted tomonitoring client 2, which (1) may display the flow rate of liquid fromthe liquid container 5 in a user interface either locally on themonitoring client 2, or more remotely to a user interface at a nurse'sstation or a handheld communications device, (2) may trigger an auditoryor visual alarm, and/or (3) may cause the monitoring client 2 to alterthe rate of infusion of a pump 4 connected to a bag 5, by eitherterminating the infusion or otherwise changing the pumping rate Theaberrant liquid flow condition may also cause an audible alarm (and/orvibration alarm) on the infusion pump 4 or the drip detection device 8,or cause the infusion pump 4 to modify or stop the pumping, e.g., whenthe aberrant liquid flow condition exceed predefined ranges ofoperation.

The alarms may occur simultaneously on several devices or may follow apredetermined schedule. For example, when an occlusion occurs in a lineconnected to the infusion pump 4, (1) the drip detection device 8 alarmsusing its internal speaker and an internal vibration motor, (2)thereafter, the infusion pump 4 alarms using its internal speaker and aninternal vibration motor, (3) next, the monitoring client 2 alarms usingits internal speaker and an internal vibration motor, and (4) finally, aremote communicator (e.g., a smart phone, blackberry-based phone,Android-based phone, iphone, etc.) alarms using its internal speaker andan internal vibration motor. In some embodiments, the syringe pump 10may be connected to the drip detection device 8 and detect aberrantliquid flow conditions as described above.

In some embodiments, the syringe pump 10 may be programmable to allowfor continued operation at a predetermined pumping rate shouldcommunications fail between the monitoring client 2 and the syringe pump10, either because of a malfunction in the monitoring client 2, in thecommunications channel between the monitoring client 2 and the syringepump 10, or in the syringe pump 10 itself. In some embodiments, thisindependent function option is enabled when the medication being infusedis pre-designated for not being suspended or held in the event of amalfunction in other parts of the system. In some embodiments, thesyringe pump 10 is programmed to operate independently in a fail safemode and may also be configured to receive information from a dripdetection device 8 directly, rather than through a monitoring client 2(e.g., in embodiment where the drip detection device 8 is used inconjunction with the syringe pump 10); with this option, the syringepump 10 may be programmed, in some embodiments, to stop an infusion ifthe drip detection device 8 detects an aberrant flow condition (such as,e.g., a free-flow condition or an air bubble present in the infusionline). In some embodiments, one or more of the pumps 4, 6, and 10 mayhave internal liquid flow meters and/or can operate independently as astand-alone device. Additionally or alternatively, an internal liquidflow meter of the syringe pump 10 may be independently determined by aflow meter of the drip detection device 8 by the monitoring client 2, inembodiments where the devices 8 and 10 are used together.

The monitoring client 2 may also remotely send a prescription to apharmacy. The prescription may be a prescription for infusing a fluidusing the syringe pump 10. The pharmacy may include one or morecomputers connected to a network, e.g., the internet, to receive theprescription and queue the prescription within the one or morecomputers. The pharmacy may use the prescription to compound the drug(e.g., using an automated compounding device coupled to the one or morecomputers or manually by a pharmacists viewing the queue of the one ormore computers), pre-fill a fluid reservoir or cartridge of a syringepump 10, and/or program the syringe pump 10 (e.g., a treatment regime isprogrammed into the syringe pump 10) at the pharmacy in accordance withthe prescription. The reservoir or cartridge may be automatically filledby the automated compounding device and/or the syringe pump 10 may beautomatically programmed by the automated compounding device. Theautomated compounding device may generate a barcode, RFID tag and/ordata. The information within the barcode, RFID tag, and/or data mayinclude the treatment regime, prescription, and/or patient information.The automated compounding device may: attach the barcode to the syringepump 10 or to the reservoir, cartridge, or disposable portion of thesyringe pump 10; attach the RFID tag to the syringe pump 10 or thereservoir, cartridge, or disposable portion of the syringe pump 10;and/or program the RFID tag or memory within the syringe pump 10 or thereservoir, cartridge, or disposable portion of the syringe pump 10 withthe information or data. The data or information may be sent to adatabase that associates the prescription with the syringe pump 10 orthe reservoir, cartridge, or disposable portion of the syringe pump 10,e.g., using a serial number or other identifying information within thebarcode, RFID tag, or memory.

The syringe pump 10 may have a scanner, e.g., an RFID interrogator thatinterrogates a reservoir, disposable portion, or cartridge of thesyringe pump 10 to determine that it is the correct fluid within thefluid reservoir or it is the correct fluid reservoir, disposable portionor cartridge, the treatment programmed into the syringe pump 10corresponds to the fluid within the fluid reservoir, disposable portionor cartridge, and/or the syringe pump 10 and reservoir, disposableportion or cartridge of the syringe pump 10 are correct for theparticular patient (e.g., as determined from a patient's barcode, RFID,or other patient identification). For example, a serial number of areservoir, disposable portion as scanned by the syringe pump 10 iscompared to a serial number in electronic medical records to determineif it correctly corresponds to a patient's serial number within theelectronic medical records; the syringe pump 10 may scan a RFID tag orbarcode of a patient to obtain a serial number of a patient which isalso compared to the patient's serial number within the electronicmedical records (e.g., the serial number of a reservoir, disposableportion, or cartridge of the syringe pump 10 or a serial number storedwithin memory of the syringe pump 10 should be associated with thepatient's serial number as scanned within the electronic medicalrecords). The syringe pump 10 may issue an error or alarm if the serialnumbers do not match, in some specific embodiments. Additionally oralternatively, the monitoring client 2 may scan the reservoir,disposable portion, cartridge, or syringe pump 10 to determine that itis the correct fluid within the fluid reservoir, it is the correct fluidreservoir, the treatment programmed into the syringe pump 10 correspondsto the fluid within the fluid reservoir or cartridge, and/or the fluidreservoir and syringe pump 10 are correct for the particular patient(e.g., as determined from a patient's barcode, RFID, or other patientidentification). Additionally or alternatively, the monitoring client 2or syringe pump 10 may interrogate an electronic medical recordsdatabase and/or the pharmacy to verify the prescription or download theprescription, e.g., using a barcode serial number on the syringe pump10, or a reservoir, cartridge, or disposable portion of the syringe pump10.

The liquid being delivered to a patient may be monitored by themonitoring client 2 to determine if all the medications being deliveredare safe for the patient. For example, the monitoring client 2 may logthe medication delivered from the syringe pump 10 as communicated by thesyringe pump 10 to the monitoring client 2, and the monitoring client 2may also log the medication being delivered by the infusion pumps 4 and6, and/or the microinfusion pump 9. The monitoring client 1 may make adetermination from the logged data to determine if the aggregate amountsand types of medication being delivered are safe. For example, themonitoring client 2 may determine if the IV bag 5 is contraindicatedwith the medication in the syringe pump 10. Additionally oralternatively, in some embodiments, the monitoring client 2 may monitorthe delivery of the liquid in the IV bag 8 and one or more bolusesdelivered by the syringe pump 10 to determine if the total dose exceedsa predetermined threshold, e.g., the medication in the IV bag 5 andsyringe pump 10 may be the same type or class of drug, and themonitoring client 2 may determine if the drugs are safe when combined asdelivered to the patient. The syringe pump 10 may also communicate withthe infusion pumps 4 and 6, and/or the microinfusion pump 9 to make thesame determination; In this exemplary embodiment, the syringe pump 10may communicate with the devices directly (via wirelessly or wiredcommunications) or through the monitoring client 2 (via wirelessly orwired communications). In some embodiments of the present disclosures,one or more communication modules (e.g., each having the capabilities tocommunicate via one or more protocols) may be connected to the syringepump 10 and/or may be connected together and then connected to thesyringe pump 10 to enable the syringe pump 10 to communicate via thecommunication modules.

The syringe pump 10 includes a touch screen interface 11 (which may bedetachable), a start button 12, and a stop button 13. However, in somealternative embodiments, the button 12 is a PCA button to deliver painmedicine to a patient. The user interface 11 may be used to programtreatment regimes, such as flow rates, bolus amounts, or other treatmentparameters. After a treatment regime is programmed into the syringe pump10, the syringe pump 10 may query a database (e.g., Electronic MedicalRecords (“EMR”), Drug Error Reduction System (“DERS”), or otherdatabase) to determine if the treatment regime is safe for theparticular patient or for any patient. For example, the syringe pump 10may query the EMR database (e.g., via a wireless link, wired link, WiFi,cell-phone network, or other communications technology) to determine ifthe treatment regime from the syringe pump 10 is safe based upon patientinformation stored (e.g., age, weight, allergies, condition, etc.) inthe EMR records. Additionally or alternatively, the syringe pump 10 mayquery the DERS database (e.g., via a wireless link, wired link, WiFi,cell-phone network, or other communications technology) to determine ifthe treatment regime from the syringe pump 10 is safe based uponpredetermined safety criteria in the DERS records

In some embodiments, if the treatment regime is determined to be safe, aprompt may request user confirmation of the treatment regime. After userconfirmation, the user (e.g., caregiver, nurse, or other authorizedperson) may press the start button 12. In some embodiments, the stopbutton 13 may be pressed at any time to stop treatment.

In some embodiments, if the EMR and/or DERS determines that thetreatment regime exceeds a first set of criteria, treatment may continueif the user confirms the treatment (e.g., with an additional warning,user passcode, and/or additional authentication or authorization, etc.);in this embodiment, the EMR or DERS may prevent the treatment from beingdelivered if the EMR and/or DERS determines that the treatment regimeexceeds a second set of criteria, e.g., the treatment is not safe underany circumstances for any patient, for example.

Exemplary Bedside Arrangement

FIGS. 2-9 show various views related to a system 200. FIG. 2 shows asystem 200 that includes several pumps 201, 202, and 203. The pumps 201,202, 203 can be coupled together to form a group of pumps that areconnectable to a pole 208. The system 200 includes two syringe pumps201, 202 and a peristaltic pump 203; however, other combinations ofvarious medical devices may be employed.

Each of the pumps 201, 202, 203 includes a touch screen 204 which may beused to control the pumps 201, 202, 203. One of the pumps' (e.g., 201,202, 203) touch screen 204 may also be used to coordinate operation ofall of the pumps 201, 202, 203 and/or to control the other ones of thepumps 201, 202, 203.

The pumps 201, 202, and 203 are daisy chained together such that theyare in electrical communication with each other. Additionally oralternatively, the pumps 201, 202, and/or 203 may share power with eachother or among each other; For example, one of the pumps 201, 202,and/or 203 may include an AC/DC converter that converts AC electricalpower to DC power suitable to power the other pumps.

Within the system 200, the pumps 201, 202, and 203 are stacked togetherusing respective Z-frames 207. Each of the Z-frames 207 includes a lowerportion 206 and an upper portion 205. A lower portion 206 of one Z-frame207 (e.g., the lower portion 206 of the pump 201) can engage an upperportion 205 of another Z-frame 207 (e.g., the upper portion 205 of theZ-frame 207 of the pump 202).

A clamp 209 may be coupled to one of the pumps 201, 202, 203 (e.g., thepump 202 as shown in FIG. 3). That is, the clamp 209 may be coupled toany one of the pumps 201, 202, 203. The clamp 209 is attachable to theback of any one of the pump 201, 202, 203. As is easily seen in FIG. 5,each of the pumps 201, 202, 203 includes an upper attachment member 210and a lower attachment member 211. A clamp adapter 212 facilitates theattachment of the clamp 209 to the pump 202 via a respective pump's(e.g., 201, 202, or 203) upper attachment member 210 and lowerattachment member 211. In some embodiments, the clamp adapter 212 may beintegral with the clamp 209.

FIG. 6 shows a close-up view of a portion of an interface of a clamp(i.e., the clamp adapter 212) that is attachable to the pump 202 (or topumps 201 or 203) shown in FIGS. 2-5 in accordance with an embodiment ofthe present disclosure. The clamp adapter 212 includes a hole 213 inwhich a lower attachment member 211 (see FIG. 5) may be attached to.That is, the lower attachment member 211 is a curved hook-likeprotrusion that may be inserted into the hole 213 and thereafter rotatedto secure the lower attachment member 211 therein.

As is easily seen in FIG. 7, the clamp adapter 212 also includes a latch214. The latch 214 is pivotally mounted to the clamp adapter 212 viapivots 216. The latch 214 may be spring biased via springs 218 that arecoupled to the hooks 220. Stop members 219 prevent the latch 214 frompivoting beyond a predetermined amount. After the hole 213 is insertedinto the lower attachment member 211 (see FIGS. 5 and 6), the clampadapter 212 may be rotated to bring the latch 214 towards the upperattachment member 210 such that the latch 214 is compressed down by theupper attachment member 210 until the protrusion 215 snaps into acomplementary space of the upper attachment member 210. The hooks 220help secure the clamp adapter 212 to the pump 202.

Each Z-frame 207 of the pumps 201, 202, 203 includes a recessed portion223 (see FIG. 5) and a protrusion 224 (see FIG. 8). A protrusion 224 ofthe Z-frame 207 of one pump (e.g., pumps 201, 202, or 203) may engage arecessed portion 223 of another pump to enable the pump to be stacked ontop of each other. Each of the pumps 201, 202, 203 includes a latchengagement member 221 that allows another one of the pumps 201, 202, 203to be attached thereto via a latch 222 (see FIG. 8). The latch 222 mayinclude a small spring loaded flange that can “snap” into the spaceformed under the latch engagement member 221. The latch 222 may bepivotally coupled to the lower portion 206 of the Z-frame 207.

As is seen in FIG. 3, the latch 222 of the pump 201 may be pulled towithdraw a portion of the latch 222 out of the space under the latchengagement member 221 of the pump 202. Thereafter, the pump 201 may berotated to pull out the protrusion 224 of the pump 201 out of therecessed portion 223 of the Z-frame 207 of the pump 202 such that thepump 201 may be removed from the stack of pumps 202, 203 (see FIG. 4).

Each of the pumps 201, 202, 203 includes a top connector 225 (see FIG.9) and a bottom connector 226 (see FIG. 8). The connectors 225 and 226allow the stacked pumps 201, 202, and 203 to communication between eachother and/or to provide power to each other. For example, if the batteryof the middle pump 202 (see FIG. 2) fails, then the top pump 201 and/orthe bottom pump 203 may provide power to the middle pump 202 as areserve while audibly alarming.

Exemplary Syringe Pump Embodiment and Related Bedside Arrangement

FIGS. 10-13 show several views of a syringe pump 300 in accordance withan embodiment of the present disclosure. The syringe pump 300 may have asyringe 302 loaded either facing to the left (as shown in FIGS. 10-13)or to the right (refer to FIG. 16, described below). That is, thesyringe pump 300 is a bidirectional syringe pump.

The syringe 302 may be loaded into a syringe holder 306 of the syringepump 300. The flange endpiece 310 of the syringe 302 may be placed inthe left flange receiver 311 or in the right flange receiver 312. Whenthe flange endpiece 310 is inserted into the left flange receiver 311,the syringe 302 faces towards the left outlet 308, which may hold a tubethat is fluidly coupled to the syringe 302. An engagement member 314 maybe coupled to an end fitting 315 of the syringe 302 when or after thesyringe 302 is loaded into the syringe holder 306. A threaded shaft 315that is coupled to a motor may be rotated to move the engagement member314 in any direction to discharge fluid from the syringe 302.

The syringe 302 may also be loaded to the right (not shown in FIGS.10-13). The syringe holder 306 may be moved and/or adjusted such that itis moved to the right so the syringe 302 may be loaded. The syringeholder 306 may be manually moved and/or an electric motor may move thesyringe holder 306 to the right. In some embodiments of the presentdisclosure, the syringe holder 306 extends sufficiently to the left andto the right such that no adjustment is used.

In the case where the syringe 302 is loaded facing the right, the flangeendpiece 310 is loaded into the right flange receiver 312. Theengagement member 314 thereafter moves to the right such that fluid maybe discharged through a tube that traverses through a right outlet 309.

The pump 300 may be controlled via a touch screen 304 to set the flowrate, flow profile, and/or to otherwise monitor or control the syringepump 300. A clamp 316 may be used to secure the syringe pump 300 to apole (e.g., using a screw-type clamp).

FIG. 14 shows several of the syringe pumps 300 of FIGS. 10-13 mounted ona pole 322 in accordance with an embodiment of the present disclosure.That is, FIG. 14 shows a system 320 that uses several syringe pumps 300mounted on the pole 312. The pole 322 may be used in a hospital and/orin a home setting.

FIGS. 15-16 illustrate portions 327 of the operation of the syringe pump300 of FIGS. 21-24 in accordance with an embodiment of the presentdisclosure. FIG. 15 shows the syringe 302 loaded facing the left, andFIG. 16 shows the syringe 302 loaded to the right. As shown in FIGS.15-16, a motor 326 is coupled to the threaded shaft 315 such that themotor 326 can rotate the threaded shaft 315.

A left syringe diameter sensor 324 measures the diameter of the syringe305 to estimate the cross-sectional size of the internal space of thebarrel of the syringe 302. The left syringe diameter sensor 325 may be abar that is attached to a post such that the bar is lifted to cover thesyringe 302; the post's movement out of the body of the syringe pump 300may be measured by a linear sensor to estimate the diameter of thebarrel of the syringe 302. Any linear sensor may be used including alinear potentiometer technology, an optical linear sensor technology, ahall-effect sensor technology, etc. The motor's 326 movement may therebybe correlated to fluid discharged from the syringe 302 using theestimate of the diameter of the internal space of the barrel of thesyringe 302. Similarly, the right syringe diameter sensor 325 may beused to estimate the internal diameter of the barrel of the syringe 302,which may be used to estimate the fluid discharged from the syringe 302to the right.

In some embodiments of the present disclosure, the touch screen 304requests information from the user when the syringe 302 is loaded intothe syringe pump 300 (in either the left or right configuration) and thesyringe diameter sensor 324 or 325 is used to estimate the diameter ofthe internal space of the barrel of the syringe 305; The user isprompted by a touch screen 304 request for the user to enter into thetouch screen 304 the manufacturer of the syringe 305. An internaldatabase within the syringe pump 300 may be used to narrow down therange of possible model numbers associated with an estimate of thediameter of the syringe 305. When the user enters in the manufacturer ofthe syringe 305, the database may be used to identify a particular modelnumber of the syringe 305 and/or a subset of possible model numberscorresponding to the estimate of the diameter of the syringe 305 and theuser entered information, which in turn, may provide a more accurateinternal diameter value (as stored within the database). The user may beprompted by the display on the touch screen 304 to select the syringemodel from a list or enter the model of the syringe that will deliverthe medication. The user may be guided through a selection process onthe touchscreen 304 to identify the syringe loaded into the machineusing one or more of the following aspects: syringe barrel size, plungerhead size, manufacturer names, images of syringes, and model numbers.The selection process may access a database of syringes includingmanufacturer, model, internal diameter and image. The syringe pump 300may use the identified syringe to set the internal diameter value forvolume calculations.

Exemplary Bedside Arrangements

FIGS. 17-18 illustrate several medical devices 402 mounted on a pole 403in accordance with an embodiment of the present disclosure. FIGS. 19-22show several views of the medical device 402 of FIGS. 17-18. The medicaldevice 402 is mounted to the pole via the clamp 401. The clamp 401allows the medical device 402 to be pulled out and adjusted. The medicaldevice 402 may be any medical device, such as an infusion pump, asyringe pump, a monitoring client, etc.

The medical device 402 is coupled to the pole 403 via arms 403 such thatthe medical device 402 may be pulled away from the pole (see FIG. 20)and/or pivoted on the arms 403.

FIG. 23 shows several mounts 406 mounted on a pole 405, and FIGS. 24-26show several views of a mount of FIG. 23 in accordance with anembodiment of the present disclosure.

Each of the mounts 406 includes a clamp 407 (e.g., a screw-type clamp),a first arm 408 pivotally mounted to the clamp 407, and a second arm 411pivotally mounted to the first arm 408 via a hinge 409. The end of thesecond arm 411 includes a coupling member 410 that can be coupled to amedical device.

Exemplary Battery and Speaker Test

FIG. 27 shows a circuit diagram 420 having a speaker 423 and a battery421 in accordance with an embodiment of the present disclosure. Thebattery 421 may be a backup battery and/or the speaker 423 may be abackup alarm speaker. That is, the circuit 420 may be a backup alarmcircuit, for example, a backup alarm circuit in a medical device, suchas a syringe pump.

In some embodiments of the present disclosure, the battery 421 may betested simultaneously with the speaker 423. When a switch 422 is in anopen position, a voltmeter 425 may be used to measure the open circuitvoltage of the battery 421. Thereafter, the switch 422 may be closed andthe closed-circuit voltage from the battery 421 may be measured. Theinternal resistance of the battery 421 may be estimated by using theknown impedance, Z, of the speaker 423. A processor may be used toestimate the internal resistance of the battery 421 (e.g., a processorof a syringe pump). The processor may correlate the internal resistanceof the battery 421 to the battery's 421 health. In some embodiments ofthe present disclosure, if the closed-circuit voltage of the battery 421is not within a predetermined range (the range may be a function of theopen-circuit voltage of the battery 421), the speaker 423 may bedetermined to have failed.

In some additional embodiments of the present disclosure, the switch 422may be modulated such that the speaker 423 is tested simultaneously withthe battery 421. A microphone may be used to determine if the speaker423 is audibly broadcasting a signal within predetermined operatingparameters (e.g., volume, frequency, spectral compositions, etc.) and/orthe internal impedance of the battery 421 may be estimated to determineif it is within predetermined operating parameters (e.g., the compleximpedance, for example). The microphone may be coupled to the processor.Additionally or alternatively, a test signal may be applied to thespeaker 423 (e.g., by modulating the switch 422) and the speaker's 423current waveform may be monitored by an current sensor 426 to determinethe total harmonic distortion of the speaker 423 and/or the magnitude ofthe current; a processor may be monitored these values using the currentsensor 426 to determine if a fault condition exists within the speaker423 (e.g., the total harmonic distortion or the magnitude of the currentare not within predetermined ranges).

Various sine waves, periodic waveforms, and/or signals maybe applied tothe speaker 423 to measure its impedance and/or to measure the impedanceof the battery 421. For example, a processor of a syringe pump disclosedherein may modulate the switch 422 and measure the voltage across thebattery 421 to determine if the battery 421 and the speaker 423 has animpedance within predetermined ranges; if the estimated impedance of thebattery 421 is outside a first range, the processor will determine thatthe battery is in a fault condition, and/or if the estimated impedanceof the speaker 423 is outside a second range, the processor willdetermine that the speaker 423 is in a fault condition. Additionally oralternatively, if the processor cannot determine if the battery 421 orthe speaker 423 has a fault condition, but has determined that at leastone exists in a fault condition, the processor may issue an alert oralarm that the circuit 420 is in a fault condition. The processor mayalarm or alert a user or a remote server of the fault condition. In someembodiments of the present disclosure, the syringe pump will not operateuntil the fault is addressed, mitigated and/or corrected.

Exemplary Syringe Pump Embodiment

In an example embodiment, as shown in FIG. 28, a syringe pump 500 isdepicted. The syringe pump 500 may be used to deliver an agent, such asbut not limited to, an analgesic, medicament, nutrient, chemotherapeuticagent, etc. to a patient. The syringe pump may be used to preciselydelivery a quantity of an agent to a patient or deliver a precisequantity of an agent over a period of time. The syringe pump 500 may beused in any suitable application, such as though not limited to,intravenous deliver, intrathecal delivery, intra-arterial delivery,enteral delivery or feeding, etc.

The syringe pump 500 comprises a housing 502 and a syringe pump assembly501. In the example embodiment in FIG. 28, the housing 502 issubstantially a rectangular box. In alternative embodiments, the housing502 may take any of a variety of other suitable shapes. The housing 502may be made of any of a number of materials or combination of materialsincluding, but not limited to, metal or plastic. The housing 502 may beextruded, injection molded, die cast, etc. In some embodiments, thehousing 502 may be comprised of a number of separate parts which may becoupled together by any suitable means. In some embodiments, the housing502 may be taken apart or comprise a removable panel to allow thesyringe pump 500 to be easily serviced.

As shown in FIG. 28, a syringe 504 may be seated on the syringe pumpassembly 501. The syringe 504 may be a glass, plastic, or any other typeof syringe 504. The syringe 504 may be a syringe 504 of any capacity. Insome embodiments, including the embodiment in FIG. 28, the syringe 504may be seated on a syringe seat 506 comprising part of the syringe pumpassembly 501. The syringe seat 506 may comprise a contour which allowsthe syringe 506 to be cradled by the syringe seat 506. The syringe seat506 may be made of the same material as the rest of the housing 502, adifferent material, or may be made of several materials. The syringeseat 506 may be coupled to the housing 502 by a mount 508 which may alsoserve as a spill, splash, drip, fluid, or debris guard.

In some embodiments, the syringe seat 506 may comprise part of thehousing 502. In the embodiment shown in FIG. 28, the syringe seat 506 ispart of a syringe pump assembly housing 503 of the syringe pump assembly501. In some embodiments the syringe pump assembly housing 503 may be atleast partially formed as an extrusion. In such embodiments, thecontours of the syringe seat 506 may be formed during extrusion.

The syringe pump assembly 501 may be inserted into the housing 502 ormay be coupled thereto. In the example embodiment in FIG. 28, thesyringe pump assembly 501 is mostly disposed inside the housing 502. Thesyringe seat 506, syringe barrel holder 518, barrel flange clip 520,plunger head assembly 522, and plunger tube 524, each a part of thesyringe pump assembly 501, are not disposed inside the housing 502 inthe exemplary embodiment shown in FIG. 28. In embodiments where thesyringe seat 506 is not part of the housing 502, the mount 508 maycomprise a gasket which functions as a seal to keep unwanted foreignmaterial from entering the housing 502 and getting into portions of thesyringe pump assembly 501, which are disposed inside the housing 502. Insome embodiments, the mount 508 may overhang the syringe seat 506 andmay function as a drip edge, splash guard, etc. which will shed liquidoff and away from the syringe pump 500

In some embodiments, the syringe pump 500 may be converted into adifferent device such as, though not limited to, a peristaltic largevolume pump. This may be accomplished by removing the syringe pumpassembly 501 from the housing 502 and replacing the syringe pumpassembly 501 with another desired assembly. Replacement assemblies mayinclude for example, other infusion pumps assemblies such as aperistaltic infusion pump assembly.

In some embodiments, a clamp 510 may be coupled to the housing 502. Theclamp 510 may be any type of clamp, for example, a standard pole clamp510 or a quick release pole clamp 510 (shown). The clamp 510 may be usedto keep the syringe pump 500 at a desired location on an object such asan I.V. pole. The clamp 510 may be removably coupled to the housing 502through a clamp mount 512. In some embodiments, the clamp mount 512 maycomprise any of a variety of fasteners such as screws, bolts, adhesive,hook and loop tape, snap fit, friction fit, magnets, etc. In someembodiments, the clamp 510 or a part of the clamp 510 may be formed asan integral part of the housing 502 during manufacture.

As shown in FIG. 28, the housing 502 may also include a display 514. Thedisplay 514 may function as a graphic user interface and allow a user toprogram and monitor pump operation. The display 514 may be an electronicvisual display such as a, liquid crystal display, touch screen, L.E.D.display, plasma display, etc. In some embodiments, the display may becomplimented by any number of data input means 516. In the exampleembodiment, the data input means 516 are several user depressiblebuttons. The buttons may have fixed functions such as “power”, “stop”,“silence”, “emergency stop”, “start therapy”, or “lock”. The lockfunction may lock all the user inputs to avoid inadvertent commands frombeing issued to the syringe pump 500, due to a touch screen display 514being touched, buttons being depressed or touched, or any otherinadvertent gesture. The data input means 516 of other embodiments maydiffer. In embodiments where the display 514 is a touch screen display,the data input means 516 may include a number of physically depressiblebuttons. The physically depressible button data input means 516 may be aback-up for the touch screen display 514 and may be used in the eventthat the touch screen display 514 is compromised or becomes otherwisenon-functional.

In a non-limiting example embodiment, the data input means 516 may bebuilt into the function of a touch screen display 514. The touch screendisplay may detect the position of a user's finger or fingers on thescreen. The touch screen may be a capacitive touch screen or any othertype of touch screen. The software may display virtual buttons, slides,and other controls.

The software may also detect the user's touch or the touch of a stylusto control the machine and interact with remote computers that maycommunicate with the syringe pump 500. The software may also recognizemulti-touch gestures which may control: the display, functioning of thesyringe pump 500, interaction of the syringe pump 500 with one or moreremote computers, etc. In some embodiments, the syringe pump 500 mayinclude sensors that detect user gestures when the user is not incontact with the display. These motion detection sensors may comprise adevice that transmits invisible near-infrared light, measuring its “timeof flight” after it reflects off objects. Such a measurement may allowthe syringe pump 500 to detect the location of objects and the distancefrom the syringe pump 500 to said objects. The syringe pump 500 may thusbe able to monitor and take commands via a user's limbs, hands, andfingers or movements of a user's limbs, hands, and fingers. One exampleof a motion detector is the PrimeSense 3D sensor made by the companyPrimeSense of Israel. In some embodiments, the display 514 and datainput means may be mounted onto the housing 502 during manufacture ofthe syringe pump 500. The display 514 may be removed and replaced duringservicing if necessary.

The syringe pump 500 may include a syringe barrel holder 518. Thesyringe barrel holder 518 may securely hold the syringe barrel 540against the syringe seat 506. The syringe barrel holder 518 may easilybe adjusted by a user to accommodate syringes 504 of various sizes. Insome embodiments, the syringe barrel holder 518 may be biased so as toautomatically adjust to the diameter of any size syringe 504 after thesyringe barrel holder 518 is pulled out by a user. The syringe barrelholder 518 will be further elaborated upon later in the specification.

The syringe pump 500 may also include a barrel flange clip 520. Thebarrel flange clip 520 in the example embodiment depicted in FIG. 28 isdisposed on an end of the syringe pump assembly housing 503 and iscapable of holding the syringe barrel flange 542 in place against theend of the syringe pump assembly housing 503. The barrel flange clip 520is also capable of retaining any of a variety of syringe barrel flange542 types and sizes which may be available to a user. The barrel flangeclip 520 will be further elaborated upon later in the specification. Fora more detailed description of the barrel flange clip 520, see FIG. 61and FIG. 62.

The syringe pump 500 may additionally include a plunger head assembly522. The plunger head assembly 522 may be attached to the syringe pumpassembly 501 by a plunger tube 524. In the example embodiment depictedin FIG. 28, the plunger head assembly 522 and plunger tube 524 extendout of the housing 502 toward the right of the page.

The syringe pump 500 may also comprise a downstream pressure sensor 513as shown in FIG. 28. The downstream pressure sensor 513 may comprisepart of the syringe pump assembly 501 or the housing 502. The downstreampressure sensor 513 may take pressure measurements from a fluid linei.e. tubing extending from the syringe 504 to a patient. In someembodiments, the fluid line may include a span of tubing which isdifferent from the rest of the tubing. For example, a span of the fluidline may be made of a deformable PVC material. Such embodiments may makefluid line pressures easier to determine.

The downstream pressure sensor 513 may comprise a cradle with a pressuresensor, such as a force sensor. In such embodiments, the fluid line maybe held against the cradle and pressure sensor of the downstreampressure sensor 513 by a non-deformable or deflectable structure. Thedownstream pressure sensor 513 may cause the syringe pump 500 to alarmif the detected pressure falls outside of an acceptable range. Themeasurement of the downstream pressure sensor 513 may be referencedagainst a look-up table to determine the pressure in the fluid line. Ifan abnormal pressure reading (e.g. a high pressure generated during anocclusion event beyond a predetermined threshold) is taken, a controlsystem of the syringe pump 500 may stop delivering fluid. In someembodiments, the syringe pump 500 may be caused to back up and relievesome of the pressure in response to the detection of pressuressuggestive of an occlusion.

FIG. 29 shows the syringe pump 500 from another perspective. In thisview, the display 514 and data input means 516 coupled to the housing502 face the front of the page. The clamp 510 is coupled to the housing502 by a clamp mount 512. The syringe pump assembly 501 is disposedmostly inside the housing 502. The syringe seat 506, which comprisespart of the syringe pump assembly 501, forms a substantial part of oneside of the housing 502. The mount 508 retains the syringe pump assembly501 and helps seal the interior of the housing 502 from exposure todebris. In embodiments where the mount 508 functions as a drip edge themount 508 may cover the syringe pump assembly 501 and help shed liquidaway from the interior of the housing 502. The syringe barrel clamp 518extends through the syringe seat 506. In the depicted position in FIG.29, the syringe barrel clamp 518 has been pulled away from its restingposition and is biased such that it may automatically retract backtoward the housing 502. In some embodiments, the syringe barrel clamp518 may be locked in a non-resting position, such as the positiondepicted in FIG. 31. The barrel flange clip 520 is visible and disposedon the end of the syringe pump assembly housing 503 closest to theplunger head assembly 522. The plunger tube 524 connects the plungerhead assembly 522 to the rest of the syringe pump assembly 501 asdescribed above. The downstream pressure sensor 513 is disposed on thesyringe seat 506.

In some specific embodiments, a camera 8127 is positioned to view thesyringe. The camera 8127 may be coupled to the RTP 3500 and/or to theprocessor 3600 of FIG. 59J to provide image data thereto. The camera8127 may include a CCD image sensor, a CMOS image sensor, or any othertype of imaging sensor. In some embodiment of the present disclosure,the camera 8127 includes an array of image sensors.

An image of the syringe loaded into the syringe seat 506 may bedisplayed on the display 514 as seen from the camera 8127. Theprocessors 3500 and/or 3600 may use the images from the camera 8127 to:read QR codes on the syringe to identify the syringe, detectparticulates or bubbles in the syringe, measure the location of theplunger to measure the volume delivered and thus the volume remaining,determine when the syringe state has changed, determine if the syringeis present, estimate bolus discharges, check the color of the fluid todetermine if it is the correct fluid, and/or determine if syringe ismissing or an improperly loaded.

By using frame differencing to detect motion and a Gaussian filter tohelp reduce camera's 8127 shot noise (which looks like an impurity, butsmaller), the moving impurities can be detected. To locate the syringe'splunger, the fiducials on the syringe may be used, template matching(the plunger being the template) may use pattern recognition to locatethe fiducials and thus the plunger.

FIGS. 30-34 illustrate how a user may place a syringe 504 into thesyringe pump assembly 501. The syringe pump assembly 501 is shown byitself in FIG. 30. The syringe 504 is not seated against the syringeseat 506. As shown, the plunger head assembly 522 comprises two jaws, anupper plunger clamp jaw 526 and a lower plunger clamp jaw 528. The upperplunger clamp jaw 526 and lower plunger clamp jaw 528 are in the openposition. The upper plunger clamp jaw 526 and lower plunger clamp jaw528 are capable of clamping and retaining the plunger flange 548 on theplunger 544 of the syringe 504. The upper plunger clamp jaw 526 andlower plunger clamp jaw 528 may be actuated to open or closed positionsvia rotation of a dial 530 comprising part of the plunger head assembly522. The plunger head assembly 522 may also comprise a plunger pressuresensor 532.

In FIG. 31, the syringe pump assembly 501 is again shown by itself. Thesyringe 504 which had not been seated on the syringe seat 506 in FIG. 30is seated in place on the syringe seat 506 in FIG. 31. The syringebarrel flange 542 is clipped in place by the barrel flange clip 520. Thesyringe barrel holder 518, has been pulled out so the syringe 504 may beplaced into the syringe pump assembly 501, but has not yet been allowedto automatically adjust to the diameter of the syringe barrel 540. Inthe example embodiment shown in FIG. 31, the syringe barrel holder 518has been rotated 90° clockwise from its orientation in FIG. 30 to lockit in position. Alternate embodiments may require counter-clockwiserotation, a different degree of rotation, or may not require rotation tolock the syringe barrel holder 518 in position. The plunger tube 524 andattached plunger head assembly 522 are fully extended away from the restof the syringe pump assembly 501. Since the dial 530 has not beenrotated from the orientation shown in FIG. 30, the upper plunger clampjaw 526 and the lower plunger clamp jaw 528 are still in the openposition.

In FIG. 32, the syringe pump assembly 501 is again shown by itself. Thesyringe 504 is seated against the syringe seat 506. The syringe barrelholder 518 has been rotated out of the locked position and has beenallowed to automatically adjust to the diameter of the syringe barrel540. The syringe barrel holder 518 is holding the syringe 504 in placeon the syringe pump assembly 501. The syringe 504 is additionally heldin place on the syringe pump assembly 501 by the barrel flange clip 520which retains the syringe barrel flange 542. The plunger tube 524 andattached plunger head assembly 522 are fully extended away from the restof the syringe pump assembly 501. Since the dial 530 has not beenrotated from the orientation shown in FIG. 30, the upper plunger clampjaw 526 and the lower plunger clamp jaw 528 are still in the openposition.

In FIG. 33, the syringe pump assembly 501 is again shown by itself. Thesyringe 504 is seated against the syringe seat 506. The syringe barrelholder 518 is pressing against the syringe barrel 540 and holding thesyringe 504 in place on the syringe pump assembly 501. The barrel flangeclip 520 is holding the syringe barrel flange 542 and helping to thehold the syringe 504 in place on the syringe pump assembly 501. Theamount that the plunger tube 524 extends away from the rest of thesyringe pump assembly 501 has been adjusted such that the plunger headassembly 522 is in contact with the plunger flange 548 on the syringeplunger 544. Since the dial 530 has not been rotated from theorientation shown in FIG. 30, the upper plunger clamp jaw 526 and thelower plunger clamp jaw 528 are still in the open position. The plungerflange 548 is in contact with the plunger pressure sensor 532.

In FIG. 34 the syringe pump assembly 501 is again shown by itself. Thesyringe 504 is seated against the syringe seat 506. The syringe barrelholder 518 is pressing against the syringe barrel 540 and holding thesyringe 504 in place on the syringe pump assembly 501. The barrel flangeclip 520 is clipping the syringe barrel flange 542 and helping to thehold the syringe 504 in place on the syringe pump assembly 501. Theamount that the plunger tube 524 extends away from the rest of thesyringe pump assembly 501 has been adjusted such that the plunger headassembly 522 is in contact with the plunger flange 548 on the syringeplunger 544. The dial 530 has been rotated from the orientation depictedin FIGS. 30-33. Consequentially, the upper plunger clamp jaw 526 andlower plunger clamp jaw 528 have moved to a closed position in which theplunger flange 548 of the syringe plunger 544 is retained by the plungerhead assembly 522. Since the upper plunger clamp jaw 526 and lowerplunger clamp jaw 528 close about the horizontal centerline of theplunger head assembly 522, the plunger flange 548 has been centered onthe plunger head assembly 522.

In the preferred embodiment, the upper plunger clamp jaw 526 and lowerplunger clamp jaw 528 each comprise a fin 529 as illustrated in FIG. 34.The fins 529 bow out away from the plunger head assembly 522 and towardthe left of the page (relative to FIG. 34). The fins 529 are disposedabout the upper plunger clamp jaw 526 and lower plunger clamp jaw 528such that the fins 529 are the only part of the upper plunger clamp jaw526 and lower plunger clamp jaw 528 to contact a plunger flange 548 whena syringe 504 is placed on the syringe pump assembly 501. As the upperplunger clamp jaw 526 and lower plunger clamp jaw 528 are closed down ona plunger flange 548 the thickness and diameter of the plunger flange548 determine when the upper plunger clamp jaw 526 and lower plungerclamp jaw 528 stop moving. At least some part of the fins 529 willoverhang the plunger flange 548 and ensure the plunger flange 548 isretained. Since the upper plunger clamp jaw 526 and lower plunger clampjaw 528 do not deflect, this forces the plunger flange 548 against therest of the plunger head assembly 522. That is, the angle of contact ofthe upper plunger clamp jaw 526 and lower plunger clamp jaw 528 on theplunger flange 548 results in a force with a component that pushes theplunger flange 548 against the plunger head assembly 522. This resultantforce additionally has a component which centers the plunger flange 548on the plunger head assembly 522. This is especially desirable becausesuch an arrangement does not allow for any “play” of the plunger flange548 between upper plunger clamp jaw 526 and lower plunger clamp jaw 528and the rest of the plunger head assembly 522. Additionally, such anarrangement is desirable because it not only securely holds the plungerflange 548 in place against the plunger head assembly 522, but alsodoubles as an anti-siphon mechanism. Such an arrangement furthermore,ensures that the plunger flange 548 consistently contacts the plungerpressure sensor 532. Any force component generated by the upper plungerclamp jaw 526 and lower plunger clamp jaw 528 which may affect readingsof the plunger pressure sensor 532 may be predictable and subtracted outor otherwise compensated for.

In other embodiments, the upper plunger clamp jaw 526 and lower plungerclamp jaw 528 may not comprise fins 529. Instead the upper plunger clampjaw 526 and lower plunger clamp jaw 528 overhang a portion of theplunger flange 548 when in the clamped position. The upper plunger clampjaw 526 and lower plunger clamp jaw 528 may stop moving when they abutthe cruciform which comprises the plunger stem 546. In otherembodiments, the upper plunger clamp jaw 526 and lower plunger clamp jaw528 may clamp a plunger stem 546 that need not be a cruciform. Inanother embodiment, the upper plunger clamp jaw 526 and lower plungerclamp jaw 528 may include a wedge, ramp, or tapered rib feature on thesurfaces of the jaws that faces the pump head assembly 522. The wedge,ramp or tapered rib serve to push the plunger flange 548 toward the pumphead assembly 522 until the plunger flange 548 is securely held againstthe pump head assembly 522.

To dispense the contents of the syringe 504, the syringe pump 500 mayactuate the plunger head assembly 522 to thereby push the plunger 544into the syringe barrel 540. Since the contents of the syringe 504 maynot flow through or past the plunger pusher 550, the contents of thesyringe 504 are forced out of the syringe outlet 552 as the plunger 544is advanced into the syringe barrel 540. Any pressure generated as theplunger 544 advances into the syringe barrel 540 is transmitted to theplunger pressure sensor 532. The plunger pressure sensor 532, may, insome embodiments, comprise a force sensor such as a strain beam. When anocclusion occurs, fluid within the syringe barrel 540 and/or the fluidlines prevents movement of the plunger 544. When the plunger headassembly 522 continues to advance, high forces are produced between theplunger 544 and the plunger head assembly 522. The pressure transmittedto the plunger pressure sensor 532 may have a programmed acceptablerange so that possible occlusions may be identified. If the pressureapplied to the plunger pressure sensor 532 exceeds a predeterminedthreshold, the syringe pump 500 may alarm or issue an alert.

FIG. 35 shows the plunger head assembly 522 with the upper plunger clampjaw 526 and lower plunger clamp jaw 528 in the fully closed position.The dial 530 is oriented such that the raised part of the dial 530 is ona plane substantially parallel to the top and bottom faces of theplunger head assembly 522. The plunger tube 524 is shown extending fromthe plunger head assembly 522 to the sliding block assembly 800. One endof a flex connector 562 is attached to the sliding block assembly 800. Aposition indicator mark has been placed on the dial 530 for illustrativepurposes in FIG. 35 and FIG. 36.

The view shown in FIG. 36 is similar to the view shown in FIG. 35. InFIG. 36, the dial 530 on the plunger head assembly 522 has been rotatedapproximately 135° clockwise. This rotation has in turn caused the upperplunger clamp jaw 526 and lower plunger clamp jaw 528 to separate andmove to the fully open position. In alternate embodiments, the dial 530may require more or less rotation than the approximately 135° shown inthe example embodiment to transition the upper plunger clamp jaw 526 andlower plunger clamp jaw 528 from a fully open position to a fully closedposition. The plunger head assembly may be capable of holding itself inthis position (described later in the specification).

An exploded view of the top half of the plunger head assembly 522 isshown in FIG. 37. As shown, the upper plunger clamp jaw 526 comprisestwo racks 570. In other embodiments, there may only be one rack 570. Insome embodiments, there may be more than two racks 570. When the plungerhead assembly 522 is fully assembled, the racks 570 may interdigitatewith a corresponding number of upper jaw pinion gears 572. The upper jawpinion gears 572 spin about the axis of an upper jaw drive shaft 574.The upper jaw drive shaft 574 may also comprise an upper jaw drive gear604 which will be elaborated upon later.

The plunger head assembly 522 may comprise a number of bearing surfacesfor the upper jaw drive shaft 574. In the example embodiment in FIG. 37,the plunger head assembly 522 comprises two upper bearing surfaces 576and a lower bearing surface 578 for the upper jaw drive shaft 574. Theupper bearing surfaces 576 may be coupled into the plunger head assemblyhousing top 600. The upper bearing surfaces 576 may be coupled to theplunger head assembly housing top 600 by any of a variety of meansincluding, but not limited to, screws bolts, adhesive, snap fit,friction fit, welds, a tongue in groove arrangement, pins, or may beformed as a continuous part of the plunger head assembly housing top 600(shown). The upper bearing surfaces 576 provide a bearing surface for atleast a span of the top half of the upper jaw drive shaft 574.

The lower bearing surface 578 is coupled into the plunger head assemblyhousing top 600. The lower bearing surface 578 may be coupled to theplunger head assembly housing top 600 by any suitable means such as, butnot limited to, screws 580 (shown), bolts, adhesive, snap fit, frictionfit, magnets, welds, a tongue in groove arrangement, etc. In someembodiments, the lower bearing surface 578 may be formed as a continuouspart of the plunger head assembly housing top 600. The lower bearingsurface 578 provides a bearing surface for at least a span of the bottomhalf of the upper jaw drive shaft 574.

In some embodiments, there may also be an upper dial shaft bearingsurface 651 which couples into the plunger head assembly housing top600. The upper dial shaft bearing surface 651 may be coupled into theplunger head assembly housing top 600 by any of a variety of meansincluding, but not limited to, screws, bolts, adhesive, snap fit,friction fit, welds, a tongue in groove arrangement (shown), pins, ormay be formed as a continuous part of the plunger head assembly housingtop 600. The upper dial shaft bearing surface 651 will be furtherelaborated upon later.

The upper jaw drive shaft 574 may also comprise a D-shaped span 582. TheD-shaped span 582 may be located on an end of the upper jaw drive shaft574 as shown in the example embodiment in FIG. 37. The D-shaped span 582of the upper jaw drive shaft 574 may couple into a complimentary shapedorifice in one side of a D-shaped connector 584. The D-shaped span 582of the upper jaw drive shaft 574 may not extend all the way through theD-shaped connector 584. In some embodiments, the orifice may run throughthe entire D-shaped connector 584. The other side of the D-shapedconnector 584 may couple onto a D-shaped shaft 586 projecting out of aplunger clamp jaws position sensor 588. Any rotation of the upper jawdrive shaft 574 may cause the D-shaped connector 584 to rotate as well.In turn, this may cause rotation of the D-shaped shaft 586 projectingfrom the plunger clamp jaws position sensor 588. In some embodiments,the D-shaped span 582 of the upper jaw drive shaft 574 may extenddirectly into the plunger clamp jaws position sensor 588. In suchembodiments, the D-shaped connector 584 and D-shaped shaft 586 may notbe needed. In some embodiments, the D-shaped span 582, the D-shapedconnector 584, and D-shaped shaft 586 need not be D-shaped. In someembodiments they may be have a triangular shape, square shape, starshape, etc.

In some embodiments, the plunger clamp jaws position sensor 588 maycomprise a potentiometer. As the D-shaped shaft 586 projecting from theplunger clamp jaws position sensor 588 rotates, the wiper of thepotentiometer is slid across the resistive element of the potentiometerthus varying the resistance measured by the potentiometer. Theresistance value may then be interpreted to indicate the position of theupper plunger clamp jaw 526 and lower plunger clamp jaw 528.Alternatively, the plunger clamp jaws position sensor 588 may comprise amagnet on the end of the upper jaw drive shaft 574 and a rotary encodersuch as the AS5030ATSU by Austrianmicrosytems of Austria. Alternatively,the position of the upper jaw 526 and or lower jaw 528 can be measuredwith a linear encoder or a linear potentiometer.

By obtaining a position from the plunger clamp jaws position sensor 588,the syringe pump 500 may be able to determine a number of things. Theposition may be used to indicate whether a plunger flange 548 has beenclamped by the plunger head assembly 522. The position may indicatewhether a plunger flange has been correctly clamped by the plunger headassembly 522. This may be accomplished by referencing the determinedposition against a position or a range of positions which may beacceptable for a specific syringe 504. The information about thespecific syringe 504 being used may be input by a user or may begathered by one or more other sensors comprising other parts of thesyringe pump 500.

Since the position measured by the plunger clamp jaws position sensor588 depends on the diameter and thickness of a clamped plunger flange548, the positional information may also be used to determineinformation about the specific syringe 504 being used (for example, itstype, brand, volume, etc.). This may be accomplished by referencing themeasured position against a database of positions which would beexpected for different syringes 504. In embodiments where there are anumber of sensors gathering information about the syringe 504, thepositional information generated by the plunger clamp jaws positionsensor 588 may be checked against data from other sensors to make a moreinformed decision on which specific syringe 504 is being utilized. Ifthe position measured by the plunger clamp jaws position sensor 588 doesnot correlate with data gathered by other sensors, the syringe pump 500may alarm.

As shown in FIG. 37, the plunger head assembly housing top 600 may alsohouse the plunger pressure sensor 532 mentioned earlier. The plungerpressure sensor 532 may comprise a plunger pressure sensor push plate590. The plunger pressure sensor push plate 590 may be a nub, a disc, orany other suitable shape. The plunger pressure sensor push plate 590 maybe flat or rounded. The plunger pressure sensor push plate 590 mayextend out of the plunger head assembly 522 such that it may physicallycontact a plunger flange 548 clamped against the plunger head assembly522. The plunger pressure sensor push plate 590 may directly transmitany force applied to it to a plunger pressure sensor input surface 596.In some embodiments, the plunger pressure sensor push plate 590 may beattached to a plunger pressure sensor lever 592. The plunger pressuresensor lever 592 may be pivotally coupled to a plunger pressure sensorpivot 594. The plunger pressure sensor pivot 594 may be disposed at anypoint along the length of the plunger pressure sensor lever 594. In theexample embodiment in FIG. 37, any force applied to the plunger pressuresensor push plate 590 is transmitted through the plunger pressure sensorlever 592 to the plunger pressure sensor input surface 596. In somespecific embodiments, the plunger pressure sensor lever 592 and plungerpressure sensor pivot 594 may serve to constrain the motion of theplunger pressure plate 590 to a plane perpendicular to the plungerflange 548 and minimize resistance to free movement of the plungerpressure plate 590. Although the location of the plunger pressure sensorpivot 594 in relation to the plunger pressure sensor push plate 590 doesnot multiply the force exerted against the plunger pressure sensor inputsurface 596 in FIG. 37, other embodiments may use different arrangementsto create a mechanical advantage.

The force measurement which is read via the plunger pressure sensor 532may be interpreted to determine the hydraulic pressure of the fluidbeing dispensed. This may contribute to safety of operation because thesensed fluid pressure may be useful in identifying possible occlusionsso that they may be corrected. The pressure may be monitored such thatif the pressure exceeds a predefined value, the syringe pump 500 mayalarm. The pressure measurement from the plunger pressure sensor 532 maybe checked against the pressure measurement from the downstream pressuresensor 513 (see FIG. 28) in embodiments including both a plungerpressure sensor 532 and a downstream pressure sensor 513. This may helpto ensure greater accuracy. If the pressure measurements do notcorrelate, an alarm may be generated. Additionally, since the sensorsare redundant, if one of the plunger pressure sensor 532 or downstreampressure sensor 513 fails during a therapy, the syringe pump 500 mayfunction on only one of the sensors in a fail operative mode.

As shown in FIG. 37, a number of electrical conduits 598 run to and fromthe both the plunger pressure sensor 532 and the plunger clamp jawsposition sensor 588. The conduits 598 provide power to the plungerpressure sensor 532 and plunger clamp jaws position sensor 588. Theelectrical conduits 598 also comprise the data communication pathways toand from the plunger pressure sensor 532 and the plunger clamp jawsposition sensor 588.

FIG. 38 shows an assembled view of the top half of the plunger headassembly 522. In FIG. 38, the upper plunger clamp jaw 526 is in a closedposition. The two racks 570 on the upper plunger clamp jaw 526 areengaged with the two pinion gears 572 on the upper jaw drive shaft 574such that any rotation of the upper jaw drive shaft 574 translates intolinear displacement of the upper plunger clamp jaw 526. The upper jawdrive shaft 574 is surrounded by the upper bearing surfaces 576 and thelower bearing surface 578.

The D-shaped span 582 of the upper jaw drive shaft 574 and the D-shapedshaft 586 of the plunger clamp jaws position sensor 588 are coupledtogether by the D-shaped connector 584. Any rotation of the upper jawdrive shaft 574 will cause rotation of the D-shaped span 582, D-shapedconnector 584, and D-shaped shaft 586. As mentioned above this rotationmay cause the wiper to slide across the resistive element of the plungerclamp jaws position sensor 588 in embodiments where the plunger clampjaws position sensor 588 comprises a potentiometer.

The plunger pressure sensor 532 is also shown in FIG. 38. The plungerpressure sensor push plate 590 may extend out of the plunger headassembly 522 such that it may physically contact a plunger flange 548(see FIG. 30) clamped against the plunger head assembly 522. The plungerpressure sensor push plate 590 may directly transmit any force appliedto it to a plunger pressure sensor input surface 596. In someembodiments, including the one shown in FIG. 38, the plunger pressuresensor push plate 590 may be attached to a plunger pressure sensor lever592. The plunger pressure sensor lever 592 may be pivotally coupled to aplunger pressure sensor pivot 594. The plunger pressure sensor pivot 594may be disposed at any point along the length of the plunger pressuresensor lever 592. In the example embodiment in FIG. 38, any forceapplied to the plunger pressure sensor push plate 590 is transmittedthrough the plunger pressure sensor lever 592 to the plunger pressuresensor input surface 596. Although the location of the plunger pressuresensor pivot 594 in relation to the plunger pressure sensor push plate590 does not multiply the force exerted against the plunger pressuresensor input surface 596 in FIG. 38, other embodiments may use differentarrangements to create a mechanical advantage.

The plunger head assembly housing top 600 also includes the top half ofa dial shaft passage 648 for a dial shaft 650 (not shown) which will beexplained later in the specification. In the example embodiment shown inFIG. 38, the dial shaft passage 648 passes through the right face of theplunger head assembly housing top 600.

FIG. 39 shows another assembled view of the top half of the plunger headassembly 522. As shown in FIG. 39 the plunger head assembly housing top600 may comprise upper jaw guides 569. The upper jaw guides 569 aresized and disposed such that they form a track-way in which the upperplunger clamp jaw 526 may move along. In the example embodiment, theupper jaw guides 569 are formed as a continuous part of the plunger headassembly housing top 600 and span the entire height of the side wall ofthe plunger head assembly housing top 600. In other embodiments, theupper jaw guides 569 may only span a part of the height of the side wallof plunger head assembly housing top 600.

As shown in FIG. 39, the plunger pressure sensor 532 may comprise aplunger pressure sensor force concentrator 595. In embodiments where theplunger pressure sensor push plate 590 transmits force directly to theplunger pressure sensor input surface 596, the plunger pressure sensorforce concentrator 595 may help to concentrate the force applied to theplunger pressure sensor push plate 590 while exerting it against theplunger pressure sensor input surface 596. In embodiments where theplunger pressure sensor 532 comprises a plunger pressure sensor lever592 on a plunger pressure sensor pivot 594, the plunger pressure sensorforce concentrator 595 may be on the end and face of the plungerpressure sensor lever 592 which presses against the plunger pressuresensor input surface 596. This may help to concentrate the force exertedagainst the plunger pressure sensor input surface 596 which may increaseaccuracy. It may also help to concentrate the force at the center of theplunger pressure sensor input surface 596, making measurements moreconsistent and accurate.

The bottom half of the plunger head assembly 522 and the plunger tube524 are shown in FIG. 40. As shown, the lower plunger clamp jaw 528comprises two lower plunger clamp jaw racks 610. In other embodiments,there may only be one lower plunger clamp jaw rack 610. In someembodiments, there may be more than two lower plunger clamp jaw racks610. Each lower plunger clamp jaw rack 610 interdigitates with a lowerplunger clamp jaw pinion gear 612. The lower plunger clamp jaw piniongears 612 are capable of rotating about the axis of a lower clamp jawdrive shaft 614. A lower jaw drive gear 620 is also disposed on thelower clamp jaw drive shaft 614. The lower jaw drive gear 620 will beelaborated upon later.

Similar to the upper half of the plunger head assembly 522 the lowerhalf of the plunger head assembly 522 may comprise a number of bearingsurfaces for the lower jaw drive shaft 614. In the example embodiment inFIG. 40, the plunger head assembly 522 comprises one upper bearingsurface 616 and two lower bearing surfaces 618 for the lower jaw driveshaft 614. The upper bearing surface 616 is coupled into the plungerhead assembly housing bottom 602. The upper bearing surface 616 may becoupled to the plunger head assembly housing bottom 602 by any of avariety of means including, but not limited to, screws 617 (shown),bolts, adhesive, snap fit, friction fit, welds, a tongue in groovearrangement, pins, or may be formed as a continuous part of the plungerhead assembly housing bottom 602. The upper bearing surface 616 providea bearing surface for at least a span of the top half of the lower jawdrive shaft 614.

The lower bearing surfaces 618 are coupled into the plunger headassembly housing bottom 602. The lower bearing surfaces 618 may becoupled to the plunger head assembly housing bottom 602 by any suitablemeans such as, but not limited to, screws, bolts, adhesive, snap fit,friction fit, magnets, welds, a tongue in groove arrangement, pin(shown), etc. In some embodiments, the lower bearing surfaces 618 may beformed as a continuous part of the plunger head assembly housing bottom602. The lower bearing surfaces 618 provide a bearing surface for atleast a span of the bottom half of the lower jaw drive shaft 614.

In some embodiments, there may also be a lower dial shaft bearingsurface 649 which is coupled to the plunger head assembly housing bottom602. The lower dial shaft bearing surface 649 may be coupled into theplunger head assembly housing bottom 602 by any of a variety of meansincluding, but not limited to, screws, bolts, adhesive, snap fit,friction fit, welds, a tongue in groove arrangement, pins, or may beformed as a continuous part of the plunger head assembly housing bottom602 as shown. The lower half of the dial shaft passage 648 mentionedabove is cut through the right face of the plunger head assembly housingbottom 602 The lower dial shaft bearing surface 649 and dial shaftpassage 648 will be further elaborated upon later.

As shown in FIG. 40, the plunger tube 524 may be coupled into the bottomhalf of the plunger head assembly 522. In the example embodiment shownin FIG. 40, the plunger tube 524 is coupled by two screws 630 onto aplunger tube cradle 631. In other embodiments, the number or type offastener/coupling method may be different. For example, the plunger tube524 may be coupled to the plunger tube cradle 631 by any other suitablemeans such as, but not limited to, bolts, adhesive, snap fit, frictionfit, magnets, welds, a tongue in groove arrangement, pin, etc.

The plunger tube cradle 631 may comprise arcuated ribs 633 which arearced such that they are flush with the outside surface of the plungertube 524 and support the plunger tube 524. In some embodiments, aportion of the arc of the plunger tube 524 may be eliminated on the spanof the plunger tube 524 which is coupled inside of the plunger headassembly 522 when the syringe pump 500 is fully assembled. In theembodiment shown in FIG. 40, about a 180° segment, or the upper half ofthe plunger tube 524 has been eliminated. The end of the plunger tube524 opposite the end of the plunger tube 524 coupled to the plunger tubecradle 631 may comprise a number of plunger tube cutouts 802 which willbe explained later. There may also be a conduit opening 632 near theplunger tube cutouts 802.

In FIG. 41, the dial 530 of the plunger head assembly 522 is shownexploded away from a dial shaft 650 to which it couples onto whenassembled. As shown, the dial shaft 650 comprises a square shaped end653. The square shaped end 653 of the dial shaft 650 fits into a squareshaped orifice 655 in the dial 530 such that as the dial 530 is rotated,the dial shaft 650 is caused to rotate as well. In other embodiments,the square shaped end 653 of the dial shaft 650 and square shapedorifice 655 on the dial 530 need not necessarily be square shaped, butrather D-shaped, hexagonal, or any other suitable shape.

A dial shaft gear 652 may be disposed about the dial shaft 650. As thedial shaft 650 is rotated, the dial shaft gear 652 may be caused torotate about the axis of the dial shaft 650. A dial shaft cam 654 may beslidably coupled to the dial shaft 650 such that the dial shaft cam 654is capable of sliding along the axial direction of the dial shaft 650and the dial shaft 650 freely rotates inside the dial shaft cam 654. Thedial shaft cam 654 may comprise one or more dial shaft cam ears 656. Thedial shaft cam ears 656 may also be referred to as dial shaft cam guidessince they perform a guiding function. In the example embodiment, thedial shaft cam 654 comprises two dial shaft cam ears 656. In the exampleembodiment, the cam surface of the dial shaft cam 654 is substantially asection of a double helix. At the end of cam surface of the dial shaftcam 654 there may be one or more dial shaft cam detents 660. The end ofthe dial shaft cam 654 opposite the cam surface may be substantiallyflat.

A dial shaft cam follower 658 may be coupled into the dial shaft 650such that it rotates with the dial shaft 650. In the example embodimentshown in FIG. 41 the dial shaft cam follower 658 runs through the dialshaft 650 such that at least a portion of the dial shaft cam follower658 projects from the dial shaft 650 on each side of the dial shaft 650.This effectively creates two dial shaft cam followers 658 which areoffset 180° from each other. Each end of the dial shaft cam follower 658follows one helix of the double helix shaped cam surface of the dialshaft cam 654.

A bias member may also be placed on the dial shaft 650. In the exampleembodiment, a dial shaft compression spring 662 is placed on the dialshaft 650. The dial shaft compression spring 662 may have a coildiameter sized to fit concentrically around the dial shaft 650. In theexample embodiment depicted in FIG. 41, the dial shaft compressionspring 662 is retained on each end by dial shaft washers 664. A dialshaft retaining ring 665 may fit in an annular groove 666 recessed intothe dial shaft 650.

In FIG. 41, the end of the dial shaft 650 opposite the square shaped end653 features a peg-like projection 770. The peg-like projection 770 maycouple into a joint of a double universal joint 772. The peg-likeprojection 770 may couple into the double universal joint 772 by anysuitable means such as, but not limited to, screws, bolts, adhesive,snap fit, friction fit, magnets, welds, a tongue in groove arrangement,pin (shown), etc. The other joint of the double universal joint 772 mayalso couple onto a driven shaft 774. The other joint of the doubleuniversal joint 772 may be coupled onto the driven shaft 774 by anysuitable means such as, but not limited to, screws, bolts, adhesive,snap fit, friction fit, magnets, welds, a tongue in groove arrangement,pin (shown), etc. The dial shaft 650 and the driven shaft 774 may beoriented approximately perpendicular to each other.

In some embodiments, a driven shaft bushing 776 may be included on thedriven shaft 774. In the example embodiment shown in FIG. 41 the drivenshaft bushing 776 is a sleeve bushing. The inner surface of the drivenshaft bushing 776 comprises the bearing surface for the driven shaft774. The outer surface of the driven shaft bushing 776 may comprise anumber of driven shaft bushing projections 778 which extend outwardlyfrom the outer surface of the driven shaft bushing 776. In the exampleembodiment in FIG. 41, the driven shaft bushing projections 778 arespaced approximately 120° apart from each other along the arc of theouter surface of the driven shaft bushing 776. In the example embodimentshown in FIG. 41, the driven shaft bushing projection 778 which projectstoward the top of the page comprises a nub 780 which extends from thetop edge of the driven shaft bushing projection 778 toward the top ofthe page. The driven shaft bushing 776 is held in place on the driveshaft 774 by driven shaft retaining rings 782. One of the driven shaftretaining rings 782 may be clipped into place on the driven shaft 774 oneach side of the driven shaft bushing 776. The end of the driven shaft774 not coupled into the double universal joint 772 may comprise adriven shaft D-shaped segment 784.

When assembled, as shown in FIG. 42, the dial shaft compression spring662 biases the dial shaft cam 654 against the dial shaft cam follower658 such that the ends of the dial shaft cam follower 658 are at thebottom of the cam surface of the dial shaft cam 654. One dial shaftwasher 664 abuts the dial shaft retaining ring 665 and the other dialshaft washer 664 abuts the flat side of the dial shaft cam 654.Preferably, the distance between the dial shaft washers 664 is at nopoint greater than or equal to the resting length of the dial shaftcompression spring 662. This ensures that there is no “slop” and thatthe dial shaft cam 654 is always biased against the ends of the dialshaft cam follower 658.

As shown, the double universal joint 772 connects dial shaft 650 to thedriven shaft 774 when assembled. The driven shaft bushing 776 is clippedinto place on the driven shaft 774 by driven shaft retaining rings 782(see FIG. 41). In the embodiment depicted in FIG. 42 the dial shaft 650functions as the drive shaft for the driven shaft 774. Any rotation ofthe dial shaft 650 generated through rotation of the dial 530 will betransmitted via the double universal joint 772 to the driven shaft 774.

FIG. 43 shows the whole plunger head assembly 522 with the plunger tube524 coupled in place. The top half of the plunger head assembly 522 isexploded away from the bottom half of the plunger head assembly 522. Thebottom half of the dial shaft 650 is sitting in the lower dial shaftbearing 649 on the plunger head assembly housing bottom 602. Anotherspan of the bottom half of the dial shaft 650 is seated on the portionof the dial shaft passage 648 located on the plunger head assemblyhousing bottom 602. As shown, the dial shaft passage 648 functions as asecond bearing surface for the dial shaft 650. The square shaped end 653of the dial shaft 650 extends beyond the dial shaft passage 648 andcouples into the square shaped orifice 655 on the dial 530.

As shown in FIG. 43, the dial shaft gear 652 on the dial shaft 650interdigitates with the lower jaw drive gear 620. As the dial 530 isrotated, the dial shaft 650 and dial shaft gear 652 also rotate.Rotation is transmitted through the dial shaft gear 652 to the lower jawdrive gear 620. Rotation of the lower jaw drive gear 620 rotates thelower clamp jaw drive shaft 614 and the lower clamp jaw pinion gears 612on the lower clamp jaw drive shaft 614. Since the lower clamp jaw piniongears 612 interdigitate with the lower plunger clamp jaw racks 610, anyrotation of the lower clamp jaw pinion gears 612 is translated intolinear displacement of the lower plunger clamp jaw 528. Thus, in theshown embodiment, rotating the dial 530 is the means by which a user mayactuate the lower plunger clamp jaw 528 to an open or clamped position.

In the embodiment shown in FIG. 43, rotation of the dial 530 also causesa linear displacement of the dial shaft cam 654 away from the dial 530and in the axial direction of the dial shaft 650. As shown in theexample embodiment, the upper bearing surface 616 for the lower clampjaw drive shaft 614 comprises a dial shaft cam ear slit 690 whichfunctions as a track for a dial shaft cam ear 656. One of the dial shaftcam ears 656 projects into the dial shaft cam ear slit 690. This ensuresthat the dial shaft cam 654 may not rotate with the dial 530 and dialshaft 650 because rotation of the dial shaft cam ear 656 is blocked bythe rest of the upper bearing surface 616 for the lower clamp jaw driveshaft 614.

The dial shaft cam ear slit 690 does, however, allow the dial shaft cam654 to displace linearly along the axial direction of the dial shaft650. As the dial 530 and dial shaft 650 are rotated, the dial shaft camfollower 658 also rotates. The dial shaft cam follower's 658 location onthe dial shaft 650 is fixed such that the dial shaft cam follower 658 isincapable of linear displacement. As the ends of the dial shaft camfollower 658 ride up the cam surface of the dial shaft cam 654, the dialshaft cam 654 is forced to displace toward the right face of the plungerhead assembly housing bottom 602 (relative to FIG. 43). The dial shaftcam ears 656 also slide in this direction within the dial shaft cam earslit 690. This causes the dial shaft compression spring 662 to compressbetween the dial shaft washer 664 abutting the dial shaft cam 654 andthe dial shaft washer 664 abutting the dial shaft retaining ring 665.The restoring force of the dial shaft compression spring 662 serves tobias the dial 530, and all parts actuated by the dial 530 to theiroriginal positions prior to any dial 530 rotation. If the dial 530 isreleased, the dial 530 and all parts actuated by the dial 530 will becaused to automatically return to their original orientations prior toany dial 530 rotation due to the expansion of the compressed dial shaftcompression spring 662. In the example embodiment, the original positionprior to any dial 530 rotation, is the position depicted in FIG. 35where the upper plunger clamp jaw 526 and lower plunger clamp jaw 528are fully closed.

In some embodiments, including the embodiment shown in FIG. 43, the dialshaft cam 654 may comprise a dial shaft cam detent 660 along the camsurface of the dial shaft cam 654. The dial shaft cam detent 660 mayallow a user to “park” the dial shaft cam follower 658 at a desiredpoint along the cam surface of the dial shaft cam 654. In the exampleembodiment, the dial shaft cam detent 660 may be reached by the dialshaft cam follower 658 when the dial 530 has been fully rotated. Whenthe dial shaft cam follower 658 is in the dial shaft cam detent 660, thedial shaft compression spring 662 may not automatically return the dial530 and all parts actuated by the dial 530 to their orientation prior toany rotation of the dial 530. A user may need to rotate the dial 530such that the dial shaft cam follower 658 moves out of the dial shaftcam detent 660 before the restoring force of the compressed dial shaftcompression spring 662 may be allowed to expand the dial shaftcompression spring 662 to a less compressed state.

FIG. 44 shows a similar view to the view illustrated in FIG. 43. In FIG.44, the plunger head assembly housing top 600 and some parts comprisingthe top half of the plunger head assembly 522 are not visible. Among theparts that are visible are the upper dial shaft bearing 651, upper clampjaw drive shaft 574, the upper clamp jaw pinion gears 572, and the upperjaw drive gear 604. As shown in FIG. 44, when assembled the dial shaft650 is sandwiched between the upper dial shaft bearing 651 and lowerdial shaft bearing 649, the dial shaft gear 652 on the dial shaft 650interdigitates with the upper jaw drive gear 604. As the dial 530 isrotated, the dial shaft 650 and dial shaft gear 652 also rotate.Rotation is transmitted through the dial shaft gear 652 to the upper jawdrive gear 604. Rotation of the upper jaw drive gear 604 rotates theupper clamp jaw drive shaft 574 and the upper clamp jaw pinion gears 572on the upper clamp jaw drive shaft 574.

Referring back to FIG. 38, the upper clamp jaw pinion gears 572interdigitate with the upper plunger clamp jaw racks 570. Any rotationof the upper clamp jaw pinion gears 572 is translated into lineardisplacement of the upper plunger clamp jaw 526. Thus rotation of thedial 530 is the means by which a user may actuate the upper plungerclamp jaw 526 (not shown in FIG. 44) to an open or clamped position.

The lower bearing surface 578 for the upper jaw drive shaft 574 is alsovisible in FIG. 44. The lower bearing surface 578 for the upper jawdrive shaft 574 may comprise a second dial shaft cam ear slit 690 inembodiments where the dial shaft cam 654 comprises more than one dialshaft cam ear 656. The second dial shaft cam ear slits 690 may functionsas a track for a dial shaft cam ear 656. One of the dial shaft cam ears656 projects into the second dial shaft cam ear slit 690. This ensuresthat the dial shaft cam 654 may not rotate with the dial 530 and dialshaft 650 because rotation of the dial shaft cam ear 656 is blocked bythe rest of the lower bearing surface 578 for the upper clamp jaw driveshaft 574.

The second dial shaft cam ear slit 690 does, however, allow the dialshaft cam 654 to displace linearly along the axial direction of the dialshaft 650. As the dial 530 and dial shaft 650 are rotated, the dialshaft cam follower 658 also rotates. The dial shaft cam follower's 658location on the dial shaft 650 is fixed such that the dial shaft camfollower 658 is incapable of linear displacement. As the ends of thedial shaft cam follower 658 ride up the cam surface of the dial shaftcam 654, the dial shaft cam 654 is forced to displace toward the rightface of the plunger head assembly housing bottom 602 (relative to FIG.44). A dial shaft cam ear 656 also slides in this direction within thesecond dial shaft cam ear slit 690. This causes the dial shaftcompression spring 662 to compress between the dial shaft washer 664abutting dial shaft cam 654 and the dial shaft washer 664 abutting thedial shaft retaining ring 665. The dial shaft compression spring 662,dial 530, and all parts actuated by the dial 530 may then behave per theabove description.

In some embodiments, the upper jaw drive gear 604 (best shown in FIG.37) and lower jaw drive gear 620 (best shown in FIG. 43) may besubstantially identical gears. Additionally, the upper jaw pinion gears572 (best shown in FIG. 37) and lower clamp jaw pinion gears 612 (bestshown in FIG. 40) may be substantially identical gears. In suchembodiments, the upper plunger clamp jaw 526 and lower plunger clamp jaw528 (see FIGS. 30-34) will experience an equal amount of lineardisplacement per degree of rotation of the dial 530. Since the point ofinterdigitation of the upper jaw drive gear 604 on dial shaft gear 652is opposite the point of interdigitation of the lower jaw drive gear 620on the dial shaft gear 652, the upper plunger clamp jaw 526 and lowerplunger clamp jaw 528 will linearly displace in opposite directions.

FIG. 45 shows a view similar to the view shown in FIG. 44. FIG. 45depicts an assembled view of the plunger head assembly 522 from aslightly different perspective. As shown in FIG. 45, the dial 530 iscoupled to the dial shaft 650. The dial shaft gear 652 is in aninterdigitating relationship with both the upper jaw drive gear 604 andthe lower jaw drive gear 620. The upper jaw drive gear 604 is disposedon the upper jaw drive shaft 574 along with two upper jaw pinion gears572. The upper jaw pinion gears 572 may be spaced apart by the lowerbearing surface 578 for the upper jaw drive shaft 574 as shown in FIG.45.

The plunger pressure sensor 532 in the embodiment depicted in FIG. 45comprises a plunger pressure sensor push plate 590 which extends out ofthe plunger head assembly 522 such that it may physically contact aplunger flange 548 (as shown in FIG. 34) clamped against the plungerhead assembly 522. The plunger pressure sensor push plate 590 isattached to a plunger pressure sensor lever 592. The plunger pressuresensor lever 592 is pivotally coupled to a plunger pressure sensor pivot594. The plunger pressure sensor pivot 594 is disposed at the left endof the plunger pressure sensor lever 594 (relative to FIG. 45). In theexample embodiment in FIG. 45, any force applied to the plunger pressuresensor push plate 590 is transmitted through the plunger pressure sensorlever 594 to the plunger pressure sensor input surface 596. Although thelocation of the plunger pressure sensor pivot 594 in relation to theplunger pressure sensor push plate 590 does not multiply the forceexerted against the plunger pressure sensor input surface 596 in FIG.45, other embodiments may use different arrangements to create amechanical advantage. The plunger pressure sensor 532 in FIG. 45 alsocomprises a plunger pressure sensor force concentrator 595 which is asmall projection extending from the plunger pressure sensor lever 592 tothe plunger pressure sensor input surface 596. The plunger pressuresensor force concentrator 595 concentrates force exerted against theplunger pressure sensor input surface 596 to help promote a moreaccurate pressure reading.

FIG. 46 shows a close up of how the upper jaw drive shaft 574 isconnected to the D-shaped shaft 586 projecting from the plunger clampjaws position sensor 588. In the embodiment depicted in FIG. 46, theupper jaw drive shaft 574 comprises a D-shaped span 582. The D-shapedspan 582 of the upper jaw drive shaft 574 projects into a complimentaryshaped orifice in the D-shaped connector 584. The D-shaped connector 584in FIG. 46 is shown in cross-section. A D-shaped shaft 586 projectingout of the plunger clamp jaws position sensor 588 also projects into theD-shaped connector 584. Any rotation of the upper jaw drive shaft 574may cause the D-shaped connector 584 to rotate as well. In turn, thismay cause rotation of the D-shaped shaft 586 projecting from the plungerclamp jaws position sensor 588. As mentioned above this rotation maycause the wiper to slide across the resistive element of the plungerclamp jaws position sensor 588 in embodiments where the plunger clampjaws position sensor 588 comprises a potentiometer.

FIG. 46 also shows the dial shaft 650 connected to the double universaljoint 772. As shown in the example embodiment in FIG. 46, the drivenshaft 774 is also coupled to the double universal joint projects downthe interior of the hollow plunger tube 524. The nub 780 on the drivenshaft bushing projection 778 of the driven shaft bushing 776 is seatedin a plunger tube notch 786 recessed into the edge of the plunger tube524 to lock the nub 780 within the plunger tube notch 786. Seating thenub 780 in the plunger tube notch 786 restricts the driven shaft bushing776 from rotation because the nub 780 may not rotate through the sidesof the plunger tube notch 786. Each of the driven shaft bushingprojection 778 abuts the interior surface of the plunger tube 524 whichkeeps the driven shaft bushing 776 centered in the plunger tube 524.

The plunger tube 524 may also serve as a channel for the electricalconduits 598 to and from the plunger clamp jaws position sensor 588 andthe plunger pressure sensor 532. Since the plunger tube 524 is sealed toliquid when the syringe pump is fully assembled, the plunger tube 524protects the electrical conduits 598 from exposure to liquid. Theelectrical conduits 598 exit the plunger tube 524 through the conduitopening 632 of the plunger tube 524 shown in FIG. 47.

FIG. 47 depicts an exploded view of a sliding block assembly 800. Asshown, the plunger tube 524 which extends from the plunger head assembly522 comprises two plunger tube cutouts 802. The plunger tube cutouts 802are cut into the front and back sides of the plunger tube 524. In FIG.47, only the front plunger tube cutout 802 is visible. The plunger tubecutouts 802 allow the plunger tube to be non-rotationally coupled to thesliding block assembly 800. In the example embodiment, two plunger tubecoupling screws 804 run through a plunger tube bracket 806, down theplunger tube cutouts 802 and into a plunger tube support 808. Theplunger tube 524, is thus tightly sandwiched between the plunger tubebracket 806 and the plunger tube support 808. Any rotation of theplunger tube 524 is obstructed by plunger tube coupling screws 804 whichabut the top and bottom edges of the plunger tube cutouts 802.Similarly, any axial displacement of the plunger tube 524 is obstructedby the plunger tube coupling screws 804 which abut the sides of theplunger tube cutouts 802. In other embodiments, the plunger tube 524 maybe coupled to the sliding block assembly 800 by any other suitable meanssuch as, but not limited to, bolts, adhesive, snap fit, friction fit,magnets, welds, a tongue in groove arrangement, pin, etc.

A closer exploded view of the sliding block assembly 800 is shown inFIG. 48A. The sliding block assembly 800 comprises a number of parts.The sliding block assembly 800 comprises a half nut housing 810, abarrel cam 820, a half nut 830, and a half nut cover plate 840. The halfnut housing 810 may be manufactured from any suitable strong materialwill not significantly deform under the applied loads such as, metal,nylon, glass-filled plastics, molded plastic, a polyoxymethylene plasticsuch as Delrin, etc. The half-nut 830 is preferably fabricated frombearing metals such as brass, bronze etc that interact well withstainless steel surfaces typical of lead screws. The barrel-cam 820 ispreferably fabricated from a hard metal such as stainless to form a goodbearing pair with the half nut 830. The half nut housing 810 comprises alead screw void 810A. The lead screw void 810A allows the lead screw 850(not shown, see FIG. 48B) to pass through the half nut housing 810. Thelead screw void 810A has a diameter larger than the lead screw 850 whichensures that the lead screw 850 passes uninhibited through the leadscrew void 810A irrespective of the point on the lead screw 850 at whichsliding block assembly 800 is located. The sliding block assembly 800includes a ribbon cable 562 to receive power from and for communicationswith the circuit board 1150 (refer to FIG. 58A).

The half nut housing 810 may also comprise a guide rod bushing 810B. Theguide rod bushing 810B in the example embodiment depicted in FIG. 48A isformed as continuous piece of the half nut housing. The guide rod 852(not shown, see FIG. 48B) extends through the guide rod bushing 810B inthe half nut housing 810 with the interior surface of the guide rodbushing 810B serving as a bearing surface for the guide rod 852. In someembodiments, the guide rod bushing 810B may not be formed as acontinuous part of the half nut housing 810 but rather coupled to thehalf nut housing 810 in any number of suitable ways. The guide rodbushing 810B may be made from a lubricious material such as bronze,brass, PTFE, delrin etc, which provides a low friction surface to matewith a hard surface of a guide rod 852 (FIG. 48B).

The half nut housing 810 may also comprise a barrel cam void 810C. Thebarrel cam void 810C may be sized such that it has a diameter slightlylarger than the diameter of the barrel cam 820. When the sliding blockassembly 800 is fully assembled, the barrel cam 820 may fit into thebarrel cam void 810C on the half nut housing 810. In some embodiments,the barrel cam void 810C may extend all the way through the half nuthousing 810. In the example embodiment shown in FIG. 48A, the barrel camvoid 810C does not extend all the way through the half nut housing 810.The barrel cam void 810C may function as a bushing for the barrel cam820 when the sliding block assembly 800 is fully assembled. The barrelcam void 810C and barrel cam 820 may be manufactured with a clearancefit. In one example the diametrical clearance between the barrel camvoid 810C and the barrel cam 820 is 0.001 to 0.005 inches.

In some embodiments, including the embodiment depicted in FIG. 48A, thehalf nut housing 810 may include a half nut void 810D. The half nut void810D, may be recessed into the half nut housing 810 such that the halfnut 830 may fit in the half nut void 810D when the sliding blockassembly 800 is fully assembled. In some embodiments, the lead screwvoid 810A, barrel cam void 810C, and half nut void 810D may all be partof a single void recessed into the half nut housing 810.

The half nut housing 810 may comprise a driven shaft aperture 810E. Thedriven shaft aperture 810E extends through the half nut housing 810 andinto the barrel cam void 810C. In FIG. 48A the driven shaft D-shapedsegment or shaft collar 784 is shown protruding into the barrel cam void810C through the driven shaft aperture 810E.

The half nut housing 810 may additionally comprise a half nut housinggroove 810F. In the example embodiment in FIG. 48A, the half nut housinggroove 810F is recessed into the half nut housing 810. The half nuthousing groove 810F is recessed along the entire side of the half nuthousing 810. The half nut housing groove 810F extends in a directionparallel to the direction of elongation of the plunger tube 524, leadscrew 850, and guide rod 852 (shown, e.g., in FIG. 48B).

In some embodiments, the half nut housing 810 may comprise at least onelimit switch 810G (not shown). In the example embodiment depicted inFIG. 48A, the half nut housing 810 may comprise two limit switches 810G(not shown). One limit switch 810G is located on the front of the halfnut housing 810 and the other limit switch 810G is located on the backof the half nut housing 810. The limit switch(es) 810G may be used tolimit the range of movement of the sliding block assembly along the leadscrew 850 (FIG. 48B). The limit switches 810G will be further elaboratedupon later.

As previously mentioned, the barrel cam 820 fits into the barrel camvoid 810C in the half nut housing 810 when the sliding block assembly800 is fully assembled. As shown, the barrel cam 820 comprises aD-shaped orifice 820A which extends through the entire barrel cam 820along the axial direction of the barrel cam 820. The D-shaped orifice820A is sized and shaped to allow the barrel cam 820 to be coupled ontothe driven shaft D-shaped segment 784. When the D-shaped orifice 820A ofthe barrel cam 820 is coupled onto the driven shaft D-shaped segment 784any rotation of the driven shaft 774 and driven shaft D-shaped segment784 causes the barrel cam 820 to rotate as well. The barrel cam 820 maybe joined to the driven shaft 774 in any of the standard methodsincluding but not limited to set screws, pins, adhesive, friction fit,welds, etc.

As shown in FIG. 48A the barrel cam 820 is generally a truncatedcylinder, and comprises a barrel cam flat 820B which is cut into thebarrel cam 820 along a chord of the front facing base of the cylinder ofthe barrel cam 820. The barrel cam flat 820B may be cut such that somedistance from the barrel cam center-line so that the full diameter ofthe barrel cam 820 remains. The remaining material of barrel cam 820 onthe far side of the centerline relative to the half-nut 830B bearingsurface provides a bearing surface to transfer forces from the half-nut820 to the barrel cam void 820C along the entire length of the barrelcam 820.

The barrel cam flat 820B may not extend along the entire barrel cam 820leaving some of the cylinder of the barrel cam 820 to have anunadulterated, classic cylindrical shape. This is desirable because theclassic cylindrically shaped portion of the barrel cam 820 may act as ajournal within the barrel cam void 810C which may act as a bushing. Inthe example embodiment depicted in FIG. 48A, the barrel cam flat 820Bextends along the barrel cam 820 until a barrel cam shoulder 820Cbegins. The barrel cam shoulder 820C may extend perpendicularly from thesurface of the barrel cam flat 820B. In the example embodiment in FIG.48A, the expanse of the barrel cam 820 with the unadulterated, classiccylindrical shape is the barrel cam shoulder 820C.

As shown, the barrel cam 820 may also comprise a barrel cam pin 820D.The barrel cam pin 820D in the example embodiment in FIG. 48A projectsperpendicularly from the front facing base of the cylinder of the barrelcam 820. The barrel cam pin 820D projects from the front facing base ofthe barrel cam 820 near the chord from which the barrel cam flat 820Bhas been extended into the cylinder of the barrel cam 820.

The sliding block assembly 800 may also comprise a half nut 830 asmentioned above. In the example embodiment in FIG. 48A, the half nut 830comprises a half nut slot 835. The half nut slot 835 is sized such thatit may act as a track-way for the barrel cam pin 820D. The half nut slot835 comprises an arcuate section 835A and an end section 835B which isnot curved or arced. The half nut slot 835 may be cut into a half nutslot plate 835C which extends perpendicularly from a half nut camfollower surface 830B. The half nut cam follower surface 830B and thehalf nut slot 835 will be further elaborated on in the followingparagraphs.

The half nut 830 may comprise a guide rod bushing void 830A. The guiderod bushing void 830A of the half nut 830 allows the guide rod bushing810B to pass through the half nut 830. In the example embodiment shownin FIG. 48A, the guide rod bushing void 830A is substantially largerthan the diameter of the guide rod bushing 810B. Additionally, the guiderod bushing void 830A in the half nut 830 may have an elliptical shapeor stadium shape. Such a shape allows the guide rod bushing 810B to fitcomfortably within the guide rod bushing void 830A when the half nut 830is engaged, disengaged, or in transition between either position.

The half nut 830 may also comprise a span of half nut threads 830C. Thehalf nut threads 830C are capable of engaging the threads of the leadscrew 850 (not shown, see FIG. 48B). In the example embodiment shown inFIG. 48A, the half nut threads 830C are V-shaped threads. V-shapedthreads may be desirable because such a shape may help to self align thehalf nut threads 830C on the lead screw 850.

As mentioned above, the sliding block assembly 800 may also comprise asliding block cover plate 840. The sliding-block, cover plate 840 may becoupled onto the half nut housing 810 such that the barrel cam 820 andhalf nut 830 are kept in place within the sliding block assembly 800when the sliding block assembly 800 is fully assembled. In the exampleembodiment shown in FIG. 48A the sliding block cover plate 840 may becoupled onto the half nut housing 810 by sliding block cover platescrews 840A as shown, or by any suitable means such as, but not limitedto, bolts, adhesive, snap fit, friction fit, magnets, welds, a tongue ingroove arrangement, pin, etc. The sliding block cover plate 840 maycomprise a cover plate groove 840B to assist in guiding the half nuthousing 810. The cover plate groove 840B may be recessed into thesliding block cover plate 840. In the example embodiment shown in FIG.48A the cover plate groove 840B is recessed along an entire side edge ofthe sliding block cover plate 840. The cover plate groove 840B may sizedand disposed such that it lines up with the half nut housing groove 810Fon the half nut housing 810.

The sliding block cover plate 840 may comprise a guide rod bushingaperture 840C. The guide rod bushing aperture 840C is sized and disposedsuch that the guide rod bushing 810B may project through the guide rodbushing aperture 840C. The guide rod bushing aperture 840C may have adiameter substantially equal to, or slightly larger than, the outerdiameter of the guide rod bushing 810B.

The edge of the sliding block cover plate 840 opposite the cover plategroove 840B, may comprise a lead screw trough 840D. The lead screwtrough 840D may be an arced section recessed into the edge of thesliding block cover plate 840. The lead screw trough 840D, inconjunction with the lead screw void 810A of the half nut housing 810allows the sliding block assembly 800 to be placed on the lead screw850.

In operation, the sliding block assembly 800 may be caused to move alongthe axial direction of the lead screw 850 and guide rod 852 as a resultof lead screw 850 rotation. The sliding block assembly 800 may also bemoved along the axial direction of the lead screw 850 and guide rod 852by a user. For a user to move the sliding block assembly 800 along theaxial direction of the lead screw 850 the user may need to adjust thelocation of the plunger head assembly 522 relative to the rest of thesyringe pump assembly 501 as shown and described in relation to FIGS.32-33. This may only be done by a user when the half nut 830 is notengaged with the lead screw 850

FIG. 48B shows the half nut 830 in an engaged position on the lead screw850. The half nut housing 810, and half nut cover plate 840 visible inFIG. 48A have been removed in FIG. 48B. When the half nut 830 is inengagement with the lead screw 850, the half nut threads 830C mayoperatively be engaged with the threads of the lead screw 850. Anyrotation of the lead screw 850 may cause the half nut 830 to move in theaxial direction of the lead screw 850.

To move the half nut 830 between an engaged and disengaged position onthe lead screw 850, the barrel cam 820 must be rotated. As the barrelcam 820 is rotated, the barrel cam pin 820D may move along the half nutslot 835 in the half nut slot plate 835C. In the example embodimentshown in FIG. 48B, when the barrel cam pin 820D is located in thearcuate section 835A of the half nut slot 835, the half nut 830 isengaged with the lead screw 850. The arcuate section 835A of the halfnut slot 835 may be shaped such that any movement of the barrel cam pin820D within the arcuate section 835A of the half nut slot 835 does notresult in any movement of the half nut 830.

When the barrel cam 820 is rotated such that the barrel cam pin 820Denters the straight, end section 835B of the half nut slot 835, furtherrotation of the barrel cam 820 may cause the half nut 830 to disengagefrom the lead screw 850. The straight nature of the end section 835Bensures that the further rotation of the barrel cam 820 causes thebarrel cam pin 820D to pull the half nut 830 away from the lead screw850 until the barrel cam pin 820D reaches the end of the end section835B. Rotation of the barrel cam 820 in the opposite direction willcause the barrel cam pin 820D to push the half nut 830 back intoengagement with the lead screw 850.

In the example embodiment in FIG. 48B, when the barrel cam 820 hasdisengaged the half nut 830 from the lead screw 850, the half nut camfollower surface 830B rests in the void created by the barrel cam flat820B. When the half nut 830 is disengaged, the distance between the halfnut threads 830C and their point of full engagement on the lead screw850 is less than or equal to the length of the sagitta of thecylindrical segment removed from the barrel cam 820 to create the barrelcam flat 820B. As the barrel cam 820 is rotated to engage the half nut830 with the lead screw 850, the pin 820D in the straight, end section835B moves the half-nut toward the lead screw 850 until the half-nut 830is at least partial engaged with the lead screw 850. As the pin 820Dexits the end section 835B, the untruncated arc of barrel cam 820rotates onto the half nut cam follower surface 830B of the half nut 830.The untruncated arc of the barrel may push the half nut 830 into fullengagement with the lead screw 850 and supplements the action of thebarrel cam pin 820D in the half nut slot 835.

Referring back to the example embodiment shown in FIG. 48A, the drivenshaft 774 to which the barrel cam 820 is coupled may not deflect whenthe barrel cam 820 has engaged, disengaged, or is transitioning the halfnut 830 from an engaged or disengaged position on the lead screw 850. Asshown, the barrel cam void 810C in the half nut housing 810 supports thebarrel cam 820 when the sliding block assembly 800 is fully assembled.Consequently, any force promoting deflection of the driven shaft 774 ischecked by the barrel cam 820 abutting the sides of the barrel cam void810C. This ensures that the half nut threads 830C may not skip on thethreads of the lead screw 850 under high axial loads. It also createsminimal drag as the sliding block assembly 800 travels along the leadscrew 850 with rotation of the lead screw 850.

In some embodiments, the fit of the half nut 830 and the barrel cam 820may be adjustable. In such embodiments, a portion of the barrel camhousing 810 that defines the barrel cam void 810C may have an adjustableposition relative to the guide rod that can be adjusted for example byrotation of a set screw or other adjustment means. This may also allow auser to adjust the barrel cam 820 to an optimal or near optimalposition. Alternatively, inserts may be added to the barrel cam void810C or the barrel cam 820 may be replaced with different sized barrelcam 820 to position the half-nut 830D/barrel cam 820 interface at theoptimal location. In such a position, the barrel cam 820 may engage thehalf nut threads 830C on the lead screw 850 such that there is zero orminimal backlash without loading the half nut threads 830C against thelead screw 850 and creating excessive drag.

In alternate embodiments, the barrel cam pin 820D may be optional. Insome alternate embodiments, the barrel cam pin 820D may be replaced byone or more bias members. The bias members may bias the half nut 830 tothe disengaged position. In such embodiments, rotation of the barrel cam820 may cause the half nut 830 engage or disengage with the lead screw850. When the barrel cam flat 820B is not contacting the half nut camfollower surface 830B the one or more bias members may be overcome andthe half nut threads 830C may be engaged with the threads of the leadscrew 850. As the barrel cam flat 820B rotates onto the half nut camfollower surface 830B, the bias member(s) may act as a spring returnwhich automatically biases the half nut 830 out of engagement with thelead screw 850 and against the barrel cam flat 820B. The barrel cam 820may include a transitional cam surface between the barrel cam flat 820 Band the untruncated arc of barrel cam 820 to facilitate displacing thehalf nut 830 toward the lead screw 850. Use of the barrel cam pin 820Dmay be desirable because such an arrangement requires less torque toengage or disengage the half nut 830 than embodiments which may employone or more bias members as a substitute. Some embodiments may use boththe barrel cam pin 820D and one or more bias members to effectengagement or disengagement of the half nut 830.

In some embodiments, the bias member may bias the half nut 830 towardsthe engaged position, in which case, the barrel cam pin 820 may beconfigured to lift the half nut threads 830C off the lead screw 850.

In another alternative embodiment, the barrel cam 820 may not comprise abarrel cam pin 820D and the half nut 830 may not comprise a half nutslot 835. In such embodiments, the barrel cam flat 820B may comprise amagnet and the half nut cam follower surface 830B may also comprise amagnet. Instead of using the barrel cam pin 820D to pull the half nut830 away from the lead screw 850, the magnet on the half nut camfollower surface 830B may be attracted to the magnet on the barrel camflat 820B and be pulled off the lead screw 850 toward the barrel camflat 820B when the barrel cam 820 has been rotated the appropriateamount. In some embodiments, the barrel cam 820 may be a simple two polemagnet. In such embodiments, the barrel cam 820 may be disposed suchthat it may repel or attract a magnet on the half nut cam followersurface 830B. When like poles of the magnets face each other, the halfnut is forced into engagement with the lead screw 850. By rotating thedriven shaft 774 and therefore the magnetic barrel cam 820, oppositepoles may be made to face each other. In turn, this may cause the halfnut 830 to disengage from the lead screw 850 as it is attracted to themagnetic barrel cam 820.

In some embodiments, a magnet may be configured to bias the half nut 830towards the engaged position, in which case, the barrel cam pin 820 maybe configured to lift the half nut threads 830C off of the lead screw850.

The guide rod 852 is also visible in FIG. 48B. In FIG. 48B the guide rod852 extends in an axial direction parallel to that of the lead screw850. The guide rod passes through the guide rod bushing void 830A in thehalf nut 830. In the example embodiment, the guide rod 852 is made of ahard and durable material. For example, in some embodiments, the guiderod 852 may be made of a material such as stainless steel. In otherembodiments, the guide rod 852 may be chromium plated.

FIG. 49 shows a close up view of the half nut slot plate 835C. The halfnut slot plate 835C is transparent in the FIG. 49. The half nut slot 835is shown in the half nut slot plate 835C. As described above, the halfnut slot 835 comprises an arcuate section 835A and a straight, endsection 835B. The barrel cam 820 is shown behind the transparent halfnut slot plate 835C. As shown, the barrel cam pin 820D is located in thearcuate section 835A of the half nut slot 835. As mentioned above, whenthe barrel cam pin 820D is in the arcuate section 835A of the half nutslot 835 the half nut 830 is engaged with the lead screw 850 as shown inFIG. 48B. The barrel cam 820 is disposed in the barrel cam void 810C inthe half nut housing 810. The barrel cam void 810C acts as a bushing forthe barrel cam 820 and supports the barrel cam 820.

FIGS. 50-52 show sliding block assembly 800 with the half nut coverplate 840 and half nut 830 shown as transparent. In FIGS. 50-52, thehalf nut 830 transitions from an engaged position (FIG. 50) to adisengaged position (FIG. 52). As shown in FIG. 50 the half nut 830 isin the engaged position. The barrel cam pin 820D is located in arcuatesection 835A of the half nut slot 835. The half nut threads 830C are atthe far left extent (relative to FIGS. 50-52) of their range ofmovement. The guide rod bushing 810B of the half nut housing 810projects through the guide rod bushing void 830A of the half nut 830. Asshown, the guide rod bushing 810B is located at the far right end of theguide rod bushing void 830A. In the example embodiment shown in FIGS.50-52 the guide rod bushing void 830A in the half nut 830 is roughlystadium shaped.

The barrel cam 820 has been rotated such that the barrel cam pin 820D isabout to cross from the arcuate section 835A of the half nut slot 835and into the end section 835B of the half nut slot 835 in FIG. 51. Asshown, the half nut threads 830C have not moved from the engagedposition and are still at the far left extent (relative to FIGS. 50-52)of their range of movement. Similarly, the half nut 830 may not havemoved relative to the guide rod bushing 810B from the position depictedand described in relation to FIG. 50.

In FIG. 52 the barrel cam 820 has been rotated such that the barrel campin 820D has moved into the straight, end section 835B of the half nutslot 835. As described above, further rotation of the barrel cam 820once the barrel cam pin 820D enters the end section 835B of the half nutslot 835 causes the half nut 830 to disengage. As shown, the half nut830, and consequentially the half nut threads 830C, have moved from thefar left extent (relative to FIGS. 50-52) of their range of movement andtoward the right of the page. The half nut 830 has moved in relation tothe guide rod bushing 810B, such that the guide rod bushing 810B is nownear the far left end of the guide rod bushing void 830A.

FIG. 53 shows a cross section of most of the components comprising anembodiment of the sliding block assembly 800. The sliding block assembly800 is depicted fully assembled in FIG. 53. The lead screw 850 and guiderod 852 are not depicted in cross section in FIG. 53. As shown, the leadscrew 850 extends through the lead screw void 810A in the half nuthousing 810 and over the lead screw trough 840D in the half nut coverplate 840. The guide rod extends through the guide rod bushing 810B. Theguide rod bushing 810B extends through both the guide rod bushing void830A in the half nut 830 and the guide rod bushing aperture 840C in thehalf nut cover plate 840.

In the example embodiment shown in FIG. 53, the half nut 830 is in thedisengaged position. The half nut threads 830C are not operativelyinterdigitated with the threads of the lead screw 850. The guide rodbushing 810B is near the top of the guide rod bushing void 830A in thehalf nut 830. The half nut cam follower surface 830B is near or isabbuting (depending on the embodiment) the barrel cam flat 820B on thebarrel cam 820. Additionally, the barrel cam pin 820D is at the end ofthe straight, end section 835B of the half nut slot 835 which is cutinto the half nut slot plate 835C.

FIG. 53 also shows the D-shaped orifice 820A of the barrel cam 820coupled onto the driven shaft D-shaped segment 784 of the driven shaft774. The plunger tube 524 through which the driven shaft 774 is disposedcan be seen coupled onto the sliding block assembly 800 by means ofscrews running through the plunger tube cutouts 802 and into the plungertube support 808.

FIG. 54 shows a view of a portion of an embodiment of the syringe pumpassembly 501. At the left side of FIG. 54, a section of the plunger headassembly 522 is visible. As shown in FIG. 54, the rear face 900 of thesyringe pump assembly 501 may comprise a rear face guide rod hole 901.The rear face guide rod hole 901 may run through the entire rear face900 of the syringe pump assembly 501 at an angle perpendicular to therear face 900 of the syringe pump assembly 501. As shown, the guide rodhole 901 may be substantially cylindrical.

The rear face 900 of the syringe pump assembly 501 may comprise agearbox depression 902. As shown, the gearbox depression 902 is recessedinto the rear face 900 of the syringe pump assembly 501. In the exampleembodiment, the gearbox depression 902 is a roughly rectangular shapeddepression. In other embodiments, the gearbox depression 902 may havealternative shapes.

As shown in FIG. 54, an anti-rotation pin 904 projects out of thegearbox depression 902. The anti-rotation pin 904 in the exampleembodiment shown in FIG. 54 is cylindrical. In alternate embodiments,the anti-rotation pin 904 may take any other suitable shape. As shown inFIG. 54, the gearbox depression 902 in the rear face 900 of the syringepump assembly 501 may also comprise a lead screw void 906. The leadscrew void 906 may be cut all the way through the rear face 900 of thesyringe pump assembly 501 and allow at least a portion of the lead screw850 to project beyond of the rear face 900 of the syringe pump assembly501. As shown in the example embodiment, the section of the lead screw850 which projects beyond the rear face 900 of the syringe pump assembly501 is not threaded.

In the example embodiment shown in FIG. 54, the section of the leadscrew 850 that is visible is smaller in diameter than the lead screwvoid 906. This is desirable because it may allow a rear face lead screwbearing 908 to be placed in the lead screw void 906 to provide a bearingsurface for the lead screw 850. In the example embodiment in FIG. 54 alead screw bearing is disposed in the lead screw void 906 to provide abearing surface for the lead screw 850.

As shown, the end of the of the section of the lead screw 850 whichprojects out of the rear face 900 may comprise a threaded bore 910. Inthe example embodiment shown in FIG. 54, a gearbox attachment fastener912 is coupled into the threaded bore 910 on the end of the lead screw850. In the example embodiment, the gearbox attachment fastener 912 is ascrew with a hex socket head. In other embodiments, any other suitablefastener, or fastener head may be used.

In FIG. 55, another view of a portion of an embodiment of the syringepump assembly 501 is shown. At the left side of FIG. 55, part of theplunger head assembly 522 is also visible. The gearbox 940 is shown inplace in the gearbox depression 902 on the rear face 900 of the syringepump assembly 501. As shown, the anti-rotation pin 904 may projectthrough an anti-rotation pin hole 942 in the gearbox 940. Theanti-rotation pin 904 ensures that the gearbox 940 causes rotation ofthe lead screw 850 and that the gearbox 940 may not rotate around theaxis of the lead screw 850. As shown, the anti-rotation pin 942 does nothelp to hold the gearbox 940 against the rear face 900 of the syringepump assembly 501. In alternate embodiments, the anti-rotation pin 904may have a threaded anti-rotation pin bore 944 (not shown) similar tothat of the end of the lead screw 850 described in above in relation toFIG. 54. An anti-rotation pin gearbox fastener 946 may be threaded intothe thread anti-rotation pin bore 944 to help hold the gearbox 940against the back face 900 of the syringe pump assembly 501. The gearbox940 may be friction locked onto the lead screw 850 to ensure thatrotation of the gears in the gearbox 940 is transmitted to the leadscrew 850 with zero or minimal backlash.

In embodiments where the syringe pump assembly 501 may be removed fromthe housing 502 (see FIG. 28) and replaced with another assembly such asa peristaltic large volume pump assembly, the gearbox 940 may becompatible with a replacement assembly.

FIG. 56 shows an embodiment of the interior of the syringe pump assembly501. As shown, the front face 888 of the syringe pump assembly 501 isshown as transparent. As shown, the guide rod 852 projectsperpendicularly from the interior of the rear face 900 of the syringepump assembly 501 and toward the front of the page. The lead screw 850may similarly project into the interior of the syringe pump assembly 501through the rear face lead screw bearing 908 at an angle perpendicularto the interior of the rear face 900 of the syringe pump assembly 501.The guide rod 852 and lead screw 850 may run parallel to each other. Inthe example embodiment in FIG. 56, the lead screw 850 is offset towardthe left of the page from the guide rod 852.

As shown, one end of the guide rod 852 is seated in the rear face guiderod hole 901. The other end of the guide rod 852 is seated in the frontface 888 of the syringe pump assembly 501. In the example embodimentdepicted in FIG. 56, the end of the guide rod 852 facing the front ofthe page is smaller in diameter than the rest of the guide rod 852. Thissection of the guide rod 852 may be placed in a guide rod hole 1002 inthe front face 888 of the syringe pump assembly 501 when the syringepump assembly 501 is fully assembled. The guide rod hole 1002 may extendthrough the entire front face 888 of the syringe pump assembly 501 at anangle substantially perpendicular to the front face 888. The smallerdiameter section of the guide rod 852 may have a diameter slightlythough not substantially smaller than the diameter of the guide rod hole1002 such that the guide rod 852 may fit snuggly in the guide rod hole1002 when the syringe pump assembly 501 is assembled. The end of theguide rod 852 may be flush with the plane of the front face 888 of thesyringe pump assembly 501. Though both the guide rod hole 1002 and thesection of the guide rod 852 seated in the guide rod hole 1002 arecylindrical in the example embodiment shown in FIG. 56, their shape maydiffer in alternate embodiments.

The lead screw 850 is seated in a lead screw depression 1000 in thefront face 888 of the syringe pump assembly 501. In the exampleembodiment shown in FIG. 56, the depth of the lead screw depression 1000is substantially the thickness of the front face 888 of the syringe pumpassembly 501. In embodiments where the depth of the lead screwdepression 1000 is substantially the depth of the front face 888, acircular plateau 1004 may be raised off the front face 888 of thesyringe pump assembly 501 to accommodate the depth of the lead screwdepression 1000. The center of the circular plateau 1004 may beconcentric with the center of a cylindrical lead screw depression 1000as shown in FIG. 56. In some embodiments, the edges of the circularplateau 1004 may extend perpendicularly from the front face 888 of thesyringe pump assembly 501 to the raised circular plateau. In the exampleembodiment illustrated in FIG. 56, the edges of the circular plateau1004 curve up from the front face 888 of the syringe pump assembly 501to the circular plateau 1004.

As shown, the lead screw depression 1000 may house a front face leadscrew bearing 1006 which surrounds the end of the lead screw 850 andprovides a bearing surface for the lead screw 850. In some embodiments,such as the embodiment depicted in FIG. 56, a Belleville washer 1008 maybe seated against the bottom of the lead screw depression 1000. TheBelleville washer 1008 may ensure that there is no “play” of the leadscrew 850 when the lead screw 850 is seated in the lead screw depression1000.

In some embodiments, the Belleville washer 1008 may be replaced bynon-compliant end cap which loads the front face lead screw bearing 1006against the lead screw 850. In such embodiments, the end cap may bethreaded on its out diameter. The lead screw depression 1000 may featurecomplimentary threads to which the end cap may screw into. Again the endcap may also ensure that there is no “play” of the lead screw 850 whenthe lead screw 850 is seated in the lead screw depression 1000.

FIG. 57 shows a view of the interior of the syringe pump assembly 501.The front face 888 which is shown as transparent in FIG. 56, is notpresent in FIG. 57. As shown, the sliding block assembly 800 describedabove is in place within the syringe pump assembly 501. The guide rod852 extends through the guide rod bushing 810B in the half nut housing810. The when the half nut 830 is disengaged from the lead screw 850,the sliding block assembly 800 may be free to slide about the axialdirection of the guide rod 852.

Movement of the sliding block assembly 800 is also guided by a syringepump assembly guide rail 1010. In the example embodiment shown in FIG.57, the syringe pump assembly guide rail 1010 extends from the interiorface of the syringe seat 506. The syringe pump assembly guide rail 1010is shaped such that the half nut housing groove 810F and cover plategroove 840B on the sliding block assembly 800 may fit on the syringepump assembly guide rail 1010 and slide along the syringe pump assemblyguide rail 1010. The syringe pump assembly guide rail 1010 also ensuresthat the sliding block assembly 800 may not rotate within the syringepump assembly 501. The syringe pump assembly guide rail 1010 may beformed as part of the extrusion in embodiments where the syringe pumpassembly housing 503 is formed by extrusion.

As shown in FIG. 57, when half nut 830 of the sliding block assembly 800is engaged with the lead screw 850, the lead screw 850 may cause linearmovement of the sliding block assembly 800 along the axial direction ofthe lead screw 850. To cause linear movement of the sliding blockassembly 800, the lead screw 850 must be rotated. In the exampleembodiment in FIG. 57, the rotational motion of the lead screw 850causes the half nut 830 and consequently the sliding block assembly 800to move along the lead screw 850 due to the pitch of the threads of thelead screw 850. The amount of linear movement per 360° rotation of thelead screw 850 may vary depending on the pitch of the threads of thelead screw 850 which may differ in various embodiments.

As mentioned above, the half nut housing 810 of the sliding blockassembly 800 may comprise one or more limit switches 810G. In theexample embodiment in FIG. 57, a limit switch 810G is not shown,although it is indicated that a limit switch 810G may be located on thefront of the half nut housing 810. In other embodiments, there may bemultiple limit switches 810G which may be disposed about other portionsof the sliding block assembly 800. In embodiments where a limit switchmay be disposed on the front of the half nut housing 810, the limitswitch 810G may prevent the sliding block assembly 800 from being driveninto the front face 888 (shown in FIG. 56) of the syringe pump assembly501.

In embodiments comprising a limit switch 810G, the limit switch 810G maybe a micro switch, although hall sensors and magnets, optical sensors,etc. could also be used. In embodiments where the limit switch 810Gcomprises a micro switch, the micro switch may be actuated when thesliding block assembly 800 nears a predefined location along the leadscrew 850. In some embodiments, when the limit switch 810G is in theactuated position, the lead screw 850 may not be further rotated toadvance the sliding block assembly 800 in the direction of thepredefined location.

As shown in FIG. 57, the syringe pump assembly 501 may additionallycomprise a sliding block linear position sensor 1050 to determine thesliding block assembly's 800 location on the lead screw 850. In someembodiments, the sliding block linear position sensor 1050 may be usedto determine the amount of contents left in a syringe 504 which may bein place on the syringe pump assembly 501. In such embodiments, thesliding block linear position sensor 1050 may be used to determine aquantified volume of syringe 504 contents or may be used as a “gasgauge” which generates a more general syringe 504 contents volumereading.

In some embodiments, the sliding block linear position sensor 1050 maycomprise a linear potentiometer. In such embodiments, the wiper of thesliding block linear position sensor 1050 may be disposed such that itslides across the resistive element of the potentiometer with movementof the sliding block assembly 800 along the lead screw 850. Theresistance measured by the sliding block linear position sensor 1050 maybe used to determine the location of the sliding block assembly 800along the lead screw 850.

In some embodiments, including the example embodiment shown in FIG. 57,the sliding block linear position sensor 1050 may comprise an array ofsliding block magnetic linear position sensors 1054. The sliding blockmagnetic linear position sensors 1054 may be any suitable magneticlinear position sensor. An example of a suitable magnetic linearposition sensor is the “AS5410 Absolute Linear 3D Hall Encoder”available from Austriamicrosystems of Austria. As shown, the slidingblock assembly 800 may include a sliding block assembly magnet 1056which is mounted a suitable distance away from the sliding blockmagnetic linear position sensors 1054 and may be used in conjunctionwith the array of sliding block magnetic linear position sensors 1054 inorder to determine the location of the sliding block assembly 800 on thelead screw 850. In some embodiments, the location of the sliding blockmagnetic linear position sensors 1054 may differ. As shown, the slidingblock 800 includes a second magnet 1057 disposed such that it mayinteract with the sliding block magnetic linear position sensors 1054when they are placed in an alternate location.

FIG. 57A shows an example of a possible linear position sensor 1100arrangement to estimate the position of a sliding block assembly 800. Inthe example linear position sensor 1100 arrangement, the linear positionsensor 1100 comprises an array of magnetic linear position sensors 1102such as the “AS5410 Absolute Linear 3D Hall Encoder” available fromAustriamicrosystems of Austria mentioned above. A position changingblock 1104 (e.g., the sliding block assembly 800) is depicted at aposition along a position changing block lead screw 1106. A positionchanging block arm 1108 projects off the page as indicated by the brokenline defining its rightmost edge. An object attached to the positionchanging block arm 1108 may be caused to move with the position changingblock 1104 as the position changing block 1104 moves along the leadscrew 1106. The position changing block 1104 in FIG. 57A may beconsidered the sliding block assembly 800 in FIG. 57.

In the example linear position sensor 1100 arrangement shown in FIG.57A, the position changing block 1104 comprises a position changingblock magnet 1110. As shown, the position changing block magnet islocated on the face of the position changing block closest to the arrayof magnetic linear position sensors 1102. The position changing blockmagnet 1110 is a dipole magnet. The north pole of the position changingblock magnet 1110 is oriented to face toward the right of the page whilethe south pole faces the left of the page. As the position changingblock 1104 moves along the position changing block lead screw 1106, theposition changing block magnet 1110 also moves. This movement may bemeasured by the array of magnetic linear position sensors 1102 andanalyzed to determine an absolute location of the position changingblock 1104 along the position changing block lead screw 1106. In someembodiments, the array of magnetic linear position sensors 1102 may beused to determine differential movements of the position changing block1104.

As shown in FIG. 58 an embodiment of the sliding block assembly 800 isshown assembled with the half nut cover plate 840 (see FIG. 48) removed.The half nut 830 is depicted in the engaged position and is shown astransparent so that the half nut housing 810 and the barrel cam 820 maybe seen behind it. The driven shaft D-shaped segment 784 of the drivenshaft 774 is shown in the D-shaped orifice 820A of the barrel cam 820.The driven shaft 774 extends through the plunger tube 524 which couplesthe sliding block assembly 800 and plunger head assembly 522 together.

Referring back to FIG. 42, the driven shaft 774 couples into a doubleuniversal joint 772. The double universal joint 772 translates anyrotational motion from the dial 530 which rotates the dial shaft 650 torotational motion of the driven shaft 774. Rotational motion of thedriven shaft 774 in turn causes rotation of the barrel cam 820. Rotationof the barrel cam 820 engages or disengages the half nut 830 asdescribed above.

As also detailed above, rotation of the dial 530 causes lineardisplacement of the upper plunger clamp jaw 526 and lower plunger clampjaw 528. The dial 530 is thus multi-functional. When rotated, the dial530 both engages or disengages the half nut 830 and opens or closes theupper plunger clamp jaw 526 and lower plunger clamp jaw 528. It shouldbe noted that the arcuate section 835A of the half nut slot 835 isshaped such that the half nut 830 does not begin to disengage until thelargest plunger flange 548 (not shown) which can be accepted by theupper plunger clamp jaw 526 and lower plunger clamp jaw 528 has beenreleased by the upper plunger clamp jaw 526 and lower plunger clamp jaw528. When the plunger flange 548 (not shown) has been released and thehalf nut 830 has disengaged, the dial shaft cam follower 658 on the dialshaft 650 may sit in the dial shaft cam detents 660 of the dial shaftcam 654 as described in relation to FIG. 43. As put forth in thedetailed description of FIG. 43, this would allow a user to “park” thedial 530 in the fully rotated position where the half nut 830 isdisengaged and the upper plunger clamp jaw 526 and lower plunger clampjaw 528 are in the open position. In the example embodiment depicted inFIG. 58, when the dial 530 is in the “parked” position, a user mayremove their hand from the dial 530 and easily adjust the plunger headassembly 522 so that a syringe 504 (not shown) may be inserted onto thesyringe pump assembly 501 (see FIGS. 30-34 for example illustrations anddiscussion of syringe 504 placement onto the syringe pump assembly 501).

FIG. 59A shows an embodiment of the syringe pump assembly 501. As shown,the syringe pump assembly 501 is fully assembled. A syringe 504 isseated on the syringe seat 506 of the syringe pump assembly housing 503.The gearbox 940 is shown in place on the syringe pump assembly 501. Themotor 1200 which drives the gearbox 940 is also shown coupled to thegearbox 940. A main printed circuit board (PCB) 1150 is showntransparently on the syringe pump assembly 501. The main PCB 1150 iscoupled to the top of the syringe pump assembly housing 503. In theexample embodiment, the flex connector 562 extending from the slidingblock assembly 800 is connected to the main PCB 1150. The electricalsystem comprising the main PCB will be described in FIGS. 59A-59J.

The electrical system 4000 of the syringe pump 500 (see FIG. 28) isdescribed in a block schematic in FIGS. 59B-59J. The electrical system4000 controls the operation of the syringe pump 500 based on inputs fromthe user interface 3700 and sensors 3501. The electrical system 4000includes a power system comprised of a rechargeable main battery 3420and battery charger 3422 that plugs into the AC mains. The electricalsystem 4000 is architected to provide safe operation with redundantsafety checks, and allow the syringe pump 500 to operate in failoperative modes for some errors and fail safe for the rest.

The high level architecture of multiple processors is shown in the lastblock diagram detailing the electrical system 4000, FIG. 59J. In oneexample the electrical system 4000 is comprised of two main processors,a real time processor 3500 and a User Interface/Safety Processor 3600.The electrical system 4000 may also comprise a watch-dog circuit 3460,motor control elements 3431, sensors 3501, and input/output elements.One main processor referred to as the Real Time Processor (hereafterRTP) 3500 may control the speed and position of the motor 1200 thatrotates the lead screw 850 (see FIG. 48B). The RTP 3500 may control themotor 1200 based on input from the sensors 3501 and commands from theUser Interface & Safety Processor (hereafter UIP) 3600. The UIP 3600 maymanage telecommunications, manage the user interface 3701, and providesafety checks on the RTP 3500. The UIP 3600 may estimate the volumepumped based on the output of a motor encoder 1202 and may signal analarm or alert when the estimated volume differs by more than aspecified amount from a desired volume or the volume reported by the RTP3500. The watch dog circuit 3460 monitors the functioning of the RTP3500. If the RTP 3500 fails to clear the watch dog circuit 3460 onschedule, the watch dog 3460 may disable the motor controller 3431,sound an alarm and turn on one or a number of failure lights at the userinterface 3701. The RTP 3500 uses the sensor inputs to control the motor1200 position and speed in a closed-loop controller (further describedbelow). The telecommunications may include a WIFI driver and antenna tocommunicate with a central computer or accessories, a Bluetooth driverand antenna to communicate with accessories, tablets, cell-phones etc.and a Near Field Communication (NFC) driver and antenna for RFID tasksand a Bluetooth. In FIG. 59J these components are collectively referredto with the reference number 3721. The user interface 3701 may include adisplay 514 (see FIG. 28). In some embodiments, the display 514 may be atouch screen. In some embodiments the user interface 3701 may compriseone or more buttons or data input means 516 (see FIG. 28) via which auser may communicate with the syringe pump 500.

The detailed electrical connections and components of the electricalsystem 4000 are shown in FIGS. 59B-591. FIGS. 59B-591 also depict anumber of line traces 5000-5169 running to and from various components.A number of sensors of the syringe pump 500 are shown in FIG. 59B. Asshown, plunger position sensors 3950, a barrel diameter sensor 3951, aplunger capture potentiometer sensor 3952, a plunger force sensor 3953,and other sensors 3954 are shown. The plunger position sensors 3950 maybe any of the plunger position sensors described herein. The barreldiameter sensor 3951 may be the syringe barrel holder linear positionsensors 1540 to be described herein. The plunger capture potentiometersensor 3952 may not necessarily be a potentiometer sensor in allembodiments. In some embodiments, the plunger capture potentiometersensor 3952 may be the plunger clamp jaws position sensor 588 describedherein. The plunger force sensor 3953 may be the plunger pressure sensor532 described herein. The plunger capture potentiometer 3952 may be aswitch to detect a syringe 504 loaded into the syringe seat 506. Theabove sensors may communicate signals respective of and indicative ofwhat they are sensing to the RTP 3500 or another component.

As shown in FIG. 59C, a thermistor 3540 may provide a signal to the RTP3500 indicative of the temperature of the infusate in an infusion line.Alternatively the thermistor 3540 may measure a temperature in thesyringe pump 500 or the temperature of the circuit 4000. In differentembodiments, suitable replacement components may be used in place of thespecific parts listed in the FIGS. 59B-591. In some embodiments, theelectrical system 4000 may comprise additional components. In someembodiments the electrical system 4000 may comprises fewer componentsthan the number of components shown in FIGS. 59B-59J.

Two sensors which may be located downstream of the syringe pump 500 areshown in FIG. 59C. One sensor is an air-in-line sensor 3545. The otheris an occlusion sensor 3535. Both are connected to the RTP 3500. Thesesensors are optional. The air-in-line sensor 3545 may detect thepresence of air in the section of an infusion line in near theair-in-line sensor 3545. In an example embodiment, the air-in-linesensor 3545 may comprise an ultra-sonic sensor 3545B, a logic unit 3545Aand a signal conditioning unit 3545C. In some embodiments, the syringepump 500 may not comprise an air-in-line sensor 3545.

The occlusion sensor 3535 may measure the internal pressure of aninfusate in an infusion line. In some embodiments, the occlusion sensor3535 may be the downstream pressure sensor 513 described herein. In anexample embodiment, the occlusion sensor 3535 may comprise a forcesensor 3535B, an amplifier 3535A, a signal amplifier 3535C and a buffer3535D. The buffer 3535D may protect the RTP 3500 from over-voltages dueto high forces generated from pressures applied to the force sensor3535B. In alternative embodiments, the occlusion sensor 3535 may differ.

The watch dog circuit 3460 is shown in FIG. 59D. The watch dog circuit3460 may enabled by an I2C command from the RTP 3500. The watch dogcircuit 3460 may signal an error and disable the motor controller 3430(e.g., via chip 3434) if it does not receive a signal from the RTP 3500at a specified frequency. The watch dog circuit 3460 may signal the uservia an audible alarm. The audible alarm may be issued via an amplifier3464 and/or backup speaker 3468. The watch dog circuit 3460 may signalthe user with visual alarm LEDs 3750 (shown in FIG. 59F) if an abnormalcondition is detected. In one embodiment, the RTP 3500 must “clear” thewatchdog 3460 between 10 ms and 200 ms after the watch dog circuit's3460 last clear. In some embodiments, the watch dog circuit 3460 iscomprised of a window watchdog 3460A, a logic circuit 3460B (which mayinclude one or more flip-flop switches) and an 10 expander 3460C thatcommunicates with the RTP 3500 over an I2C bus. A backup battery 3450(see FIG. 59C) may provide power to the watch dog circuit 3460 andbackup speaker system (which may comprise an audio amplifier 3464, and abackup speaker 3468) in case the main battery 3420 (see FIG. 59E) fails.The backup battery 3450 may provide power to the RTP 3500 and UIP 3600to maintain the internal timekeeping, which may be especially desirablewhen the main battery 3420 is changed. The RTP 3500 may also monitor thevoltage of the backup battery 3450 with a switch such as the “FAIRCHILDFPF1005 LOAD SWITCH” 3452 shown in FIG. 59C.

The RTP 3500 directly controls the speed and position of the motor 1200.The motor 1200 may be any of a number of types of motors 1200 includinga brushed DC motor, a stepper motor, or a brushless DC motor. In theembodiment illustrated in FIGS. 59B-59J, the syringe pump 500 is drivenby a brushless direct current (BLDC) servo motor 1200. In one exampleembodiment, the RTP 3500 receives signals from the hall-sensors 3436 ofa brushless DC motor 1200 and does the calculations to commutate powerto the winding of the motor 1200 to achieve a desired speed or position.The commutation signals may be sent to the motor controller 3430 whichselectively connects the windings to the motor power supply 3434. Themotor 1200 may be monitored for damaging or dangerous operation viacurrent sensors 3432 and a temperature sensor 1200A.

The signals from the hall sensors 3436 may be supplied to both the RTP3500 and to an encoder 1202. In one embodiment, three hall signals aregenerated. Any two of the three hall signals may be sent to the encoder1202. The encoder 1202 may use these signals to provide a positionsignal to the UIP 3600. The UIP 3600 estimates the total volume of fluiddispensed by the syringe pump 500 from the position signal of theencoder 1202. In some specific embodiments, each syringe pump 500 may becalibrated during assembly to establish the nominal volume/stroke thatmay be stored in memory. The UIP 3600 estimated volume may then becompared at regular intervals to the volume which would be expected fora commanded therapy. In some embodiments, the interval betweencomparisons may be shorter for different infusates, for example shorthalf-life infusates. The therapy may specify, among other parameters, aflow rate, duration, and a total volume to be infused (VTBI). In anycase, the expected volume based on the programmed therapy at a giventime during that therapy may be calculated and compared to the volumeestimated by the UIP 3600. The UIP 3600 may signal an alert or alarm ifthe difference between UIP 3600 estimated volume and the expected volumefor therapy is outside of a predefined threshold. The UIP 3600 maysignal an alarm if the difference between UIP 3600 estimated volume andthe expected volume for the therapy is outside another predefinedthreshold.

The UIP 3600 may also compare the estimated volume to the volumereported by the RTP 3500. The UIP 3600 may signal an alert if thedifference between UIP 3600 estimated volume and the RTP 3500 reportedvolume is outside a predefined threshold. The UIP 3600 may signal analarm if the difference between UIP 3600 estimated volume and the RTP3500 reported volume is outside a second threshold.

In some embodiments, the UIP 3600 may compare the RTP 3500 reportedvolume to the expected volume for the therapy and signal an alert if thetwo values differ by more than a predefined threshold. The UIP 3600 maysignal an alarm if the difference between the RTP 3500 reported volumeand the expected volume for the therapy differ by more than anotherpredefined threshold. The values of the alert and alarm thresholds maybe different for comparisons between different sets of volumes. Thethresholds may be stored memory. The thresholds may vary depending on anumber of different parameters, such as, but not limited to, medication,medication concentration, clinical usage, patient, therapy type, orlocation. The thresholds may be predefined in a DERS (Drug ErrorReduction System) database and downloaded from the device gatewayserver.

Optionally, in some embodiments, a rotary encoder 5430 may be used toestimate the rotation of the motor threaded screw 1200. The motor sensor5430 may be formed by a magnet on the motor's 1200 shaft with a HallEffect sensor nearby to estimate the position of the threaded shaft.

An RFID tag 3670 (see FIG. 59E) may be connected by an I2C bus to theUIP 3600 and to a near field antenna 3955. The RFID tag 3670 may be usedby med-techs or other users or personnel to acquire or store informationwhen the syringe pump 500 is in an unpowered state. The UIP 3600 maystore service logs, error codes, etc. in the RFID tag 3670. The servicelogs, error codes, etc. may be accessible by an RFID reader. A med-tech,for example, could inspect unpowered syringe pumps 500 in storage orevaluate non-functioning syringe pumps 500 by using an RFID reader tointerrogate the RFID tag 3670. In another example, a med-tech or otherpersonnel may perform service on the syringe pump 500 and store anyrelated service information in the RFID tag 3670. The UIP 3600 may thencull the latest service information from the RFID tag 3670 and store itin memory 3605 (see FIG. 59E).

The main battery 3420 may supply all the power to the syringe pump 500.The main battery 3420 may be connected via a system power gating element3424 to the motor power supply 3434. All of the sensors and processorsdescribed herein may be powered by one of the several voltage regulators3428 (see FIG. 59E). The main battery 3420 may be charged from AC powervia a battery charger 3422 and an AC/DC converter 3426. The UIP 3600 beconnected to one or more memory chips 3605.

The UIP 3600 controls the main audio system which comprises a mainspeaker 3615 and the audio-chips 3610 (audio codec), 3612 (audioamplifier) (see FIG. 59E). The main audio system may be capable ofproducing a range of sounds indicating, for example, alerts and alarms.The audio system may also provide confirmatory sounds to facilitate andimprove user interaction with the display 514 and/or data input means516 (see FIG. 28). The main audio system may include a microphone 3617which may be used to confirm the operation of the main speaker 3615 aswell as the backup speaker 3468. The main audio system may produce oneor more tones, modulation sequences and/or patterns of sound and theaudio codec chip 3610 may compare the signal received from themicrophone 3617 to the signal sent to the main speaker 3615. The use ofone or more tones and comparison of signals may allow the system toconfirm main speaker 3615 function independently of any ambient noise.Alternatively the UIP 3600 or the audio codec 3610 may confirm that themicrophone 3617 produces a signal at the same time a signal is sent tothe speaker amplifier 3612.

The UIP 3600 may provide a range of different wireless signals fordifferent uses. The UIP 3600 may communicate with the hospital wirelessnetwork via a dual band WiFi using chips 3621, 3620, and 3622 andantennas 3720 and 3722. The spatially diverse dual antenna may bedesirable because in may be capable of overcoming dead spots within aroom due to multiple paths and cancellation. A hospital device gatewaymay communicate DERS, CQI (Continuous Quality Improvement),prescriptions, patient data, etc. to the syringe pump 500 via the WiFisystem.

The Bluetooth system using, the same chips 3621, 3620 and 3622 (see FIG.59E) and antennas 3720 and 3722 (see FIG. 59F), may provide a convenientmethod to connect auxiliaries to the syringe pump 500 that may includepulse-oximeters, blood pressure readers, bar-code readers, tablets,phones, etc. The Bluetooth may include version 4.0 to allow low powerauxiliaries which may communicate with the syringe pump 500 periodicallysuch as, for example, a continuous glucose meter that sends an updateonce a minute.

The NFC system may be comprised of an NFC controller 3624 (see FIG. 59E)and an antenna 3724 (see FIG. 59F). The NFC controller 3624 may also bereferred to as an RFID reader. The NFC system may be used to read RFIDchips identifying drugs or other inventory information. The RFID chipsmay also be used to identify patients and caregivers. The NFC controller3624 may also interact with a similar RFID reader on, for example, aphone or tablet computer to input information including prescriptions,bar-code information, patient, care-giver identities, etc. The NFCcontroller 3624 may also provide information to phone or tabletcomputers such as the syringe pump 500 history or service conditions.The RFID antennas 3720 and 3722 and/or NFC antenna 3724 may preferablybe located around or near the display 514 screen, so all interactionwith the syringe pump 500 occurs on or near the display 514 whetherreading an RFID chip or interacting with a touch screen display 514 orother data input means 516 near the display.

The UIP 3600 may include a medical grade connector 3665 (see FIG. 591)so that other medical devices may plug into the syringe pump 500 andprovide additional capabilities. The connector 3665 may implement a USBinterface.

The display 514 may include the RFID antennas 3720, 3722, the NFCantenna 3724, the display 514, the touch screen 3735, an LCD backlightdriver 3727, a light sensor 3740, a 16 channel LED driver 3745, LEDindicator lights 3747 and 3749, and three buttons 3760, 3765, 3767. Thebuttons may collectively be referred to herein as data input means 516.The display 514 may include a backlight 3727 and an ambient light sensor3740 to allow the display 514 brightness to automatically respond and/oradjust to ambient light. The first button 3760 may be the “Power”button, while another button 3765 may be an infusion stop button. Thesebuttons 3760, 3765 may not provide direct control of the syringe pump500, but rather provide a signal to the UIP 3600 to either initiate orterminate infusion. The third button 3767 may silence an alarm or alertat the main speaker 3615 and at the backup speaker 3468. Silencing thealarm or alert will not clear the fault, but may end the audible alarmor alert. The electrical system 4000 described above, or an alternativeembodiment of the electrical system 4000 described above may be usedwith the syringe pump 500 described herein.

FIG. 60 shows an exemplary embodiment of the syringe pump assembly 501.In FIG. 60 the syringe pump assembly housing 503 which is shown in FIG.59A has been removed. As shown, a syringe 504 is in place on the syringepump assembly 501 and is being held by the syringe barrel holder 518.The sliding block assembly 800 is located approximately in the middle ofthe axial length of the lead screw 850. Since the plunger tube 524connects the sliding block assembly 800 to the plunger head assembly522, the plunger head assembly 522 is at location where it has causedthe syringe plunger 544 to dispense about half of the content of thesyringe 504.

As shown, a motor 1200 is operatively coupled to the gearbox 940 in FIG.60. Rotation of the motor 1200 is transmitted through the gearbox 940 todrive the rotation of the lead screw 850. As described above, since theupper plunger clamp jaw 526 and lower plunger clamp jaw 528 are closedon the plunger flange 548, the half nut 830 is engaged with the leadscrew 850. Consequently, in the embodiment depicted in FIG. 60 as themotor 1200 causes the lead screw 850 to rotate, the sliding blockassembly 800 will travel along the axial length of the lead screw 850.As motor 1200 rotates the lead screw 850 such that the sliding blockassembly 800 moves toward the left of the page (relative to FIG. 60),the sliding block assembly's 800 movement will additionally cause theplunger tube 524 and plunger head assembly 522 to displace toward theleft of the page. As the plunger head assembly 522 displaces toward theleft of the page, the syringe plunger 544 is advanced into the syringebarrel 540 of the syringe 504 and the contents of the syringe aredispensed.

The motor 1200 may be any suitable motor 1200. As shown in FIG. 59A asmall profile pancake motor 1200 may be used to drive the rotation ofthe lead screw 850. The embodiment shown in FIG. 60 does not use apancake motor 1200. The motor 1200 shown in FIG. 60 is an alternativemotor that also has hall sensors 3436 to inform commutation of the motor1200. As shown in FIG. 60, the motor 1200 may comprise a magnet on therotor that is detected by a rotary encoder 1202. The rotary encoder 1202may be any of a variety of suitable rotary encoders 1202 such as theAS5055 by Austrianmicrosystems of Austria. In some embodiments, therotary encoder 1202 may be a magnetic. The rotary encoder 1202 may beused to monitor rotation of the lead screw 850. Information from therotary encoder 1202 may be used to determine when a given amount of thecontents of the syringe 504 has been dispensed. Additionally, the rotaryencoder 1202 may be used to determine the location of the sliding blockassembly 800 on the lead screw 850.

To ensure that the rotary encoder 1202 is functioning properly, a selftest may be preformed. The motor 1200 may be powered to move the slidingblock assembly 800 back and forth along a distance of the lead screw850. Measurements from the rotary encoder 1202 may be confirmed againstthe measurements of the sliding block assembly linear position sensor1050.

The same self test may also be used to confirm the hall sensors 3436 ofthe brushless motor 1200 are functioning properly.

As previously indicated, the syringe pump 500 includes a number ofsensor redundancies. This allows the syringe pump 500 to function in afail operative mode if deemed appropriate. In the event that the rotaryencoder 1202 fails, the hall sensors 3436 of the brushless motor 1200may be used in a fail operative mode to measure the dispensation ofsyringe 504 contents via the rotation of the motor 1200 and provide afeed-back signal for the motor controller. Alternatively the location ofthe sliding block assembly 800 along the lead screw 850 may be used in afail operative mode to measure the dispensation of syringe 504 contentsvia position of the sliding block assembly 800 and provide a feed-backsignal for the controller. Alternatively the sliding block assemblylinear position sensor 1050, may be used to monitor the dispensation ofsyringe 504 contents via position of the sliding block assembly 800 onthe lead screw and to provide a feed-back signal for the controller. Insome embodiments, the motor hall sensors 3436 or the linear slidingblock assembly linear position sensor 1050 may be used to monitor theposition of the sliding block assembly 800 on the lead screw 850 toavoid driving the sliding block assembly 800 against the pump frame.

In the event of a failure of the rotary encoder 1202, the syringe pump500 may finish a therapy if a therapy is in progress and disallow a userfrom commencing another therapy until the syringe pump 500 has beenserviced. In the event of a failure of the rotary encoder 1202 thesyringe pump 500 may alarm. In some embodiments, if the rotary encoder1202 fails and the motor 1200 is being used to deliver at a low flowrate, the syringe pump 500 may not finish the therapy. If such a failureoccurs, the syringe pump 500 may alarm and the syringe pump 500 mayfinish a therapy if a therapy is in progress and disallow a user fromcommencing another therapy until the syringe pump 500 has been serviced.The controller of the syringe pump 500 may base its decision to continuea therapy based on the risk level of the infusate being delivered to apatient. If the risk of non-delivery to a user is higher than the riskof delivering with reduced accuracy, the syringe pump 500 will deliverin a fail operative mode.

FIG. 61 shows a small volume syringe 504 in place on the syringe pumpassembly 501. Only a small portion of the syringe pump assembly 501 isvisible in FIG. 61. As shown, the syringe 504 is held in place againstthe syringe seat 506 by the syringe barrel clamp 518. The syringe barrelflange 542 is clipped in place against the syringe pump assembly 501 bythe barrel flange clip 520. The barrel flange clip 520 is slightlyoffset from the rest of the syringe pump assembly 501 such that there issmall gap between the syringe pump assembly 501 and the barrel flangeclip 520. When a user places the syringe 504 on the syringe seat 506,the user may also place the syringe barrel flange 542 into the small gapbetween the syringe pump assembly 501 and the barrel flange clip 520.

As shown in FIG. 61, the outward edge of the barrel flange clip 520 bowsout toward the left of the page. This helps to guide the syringe barrelflange 542 into the gap between the barrel flange clip 520 and thesyringe pump assembly 501. The barrel flange clip 520 may also includeone or a number of cutouts 521. In the example embodiment in FIG. 61,the cutouts 521 of the barrel flange clip comprise two valleys. Thefirst valley is recessed into the center span of the outward edge of thebarrel flange clip 520. The second valley, which is recessed into thelowest span of the first valley, is considerably smaller and shallower.In other embodiments, the cutouts 521 may be different in shape, size,etc. The plunger 544 of the small syringe 504 in FIG. 61 is locatedentirely within the cutouts 521 in the barrel flange clip 520. Withoutthe cutouts 521 in the barrel flange clip 520, the plunger 544 of thesyringe 504 would contact the outward edge of the barrel flange clip 520and obstruct user placement of the syringe barrel flange 542 into thegap between the barrel flange clip 520 and the syringe pump assembly501.

FIG. 62 shows a large volume syringe 504 in place on the syringe pumpassembly 501. Only a small portion of the syringe pump assembly 501 isvisible in FIG. 62. As shown, the syringe 504 is held in place againstthe syringe seat 506 by the syringe barrel clamp 518. The syringe barrelflange 542 is clipped in place against the syringe pump assembly 501 bythe barrel flange clip 520. The barrel flange clip 520 is slightlyoffset from the rest of the syringe pump assembly 501 such that there issmall gap between the syringe pump assembly 501 and the barrel flangeclip 520. When a user places the syringe 504 on the syringe seat 506,the user may also place the syringe barrel flange 542 into the small gapbetween the syringe pump assembly 501 and the barrel flange clip 520.

As shown in FIG. 62, the barrel flange clip 520 may also include aroughly semi-circular depression 519 which thins the barrel flange clip520. The roughly semi-circular depression 519 may be included toaccommodate the plunger flange 548 (not shown) of a syringe 504. Inembodiments where the barrel flange clip 520 includes the roughlysemi-circular depression 519, the plunger 544 may be advanced a distanceequal to the depth of the semi-circular depression 519 further into thesyringe barrel 540. This is desirable because it allows more of thecontents of the syringe 504 to be administered to a patient.

As shown in FIG. 62, the barrel flange clip 520 may include a barrelflange sensor 700. The barrel flange sensor 700 may be comprised of anynumber of suitable sensors. In some embodiments, the barrel flangesensor 700 may function in a binary (yes/no) manner to indicate whethera syringe barrel flange 542 is clipped by the barrel flange clip 520. Insome embodiments, the barrel flange sensor 700 may comprise a microswitch which is actuated as the syringe barrel flange 524 is placed inthe gap between the syringe pump assembly 501 and the barrel flange clip520. In other embodiments, the barrel flange sensor 700 may comprise aphotosensor. Insertion of the syringe barrel flange 542 into the gapbetween the syringe pump assembly and the barrel flange clip 520 mayblock a light source for the barrel flange sensor 700 in embodimentswhere the barrel flange sensor 700 comprises a photosensor. In suchembodiments, the barrel flange sensor 700 may indicate a syringe barrelflange 542 is clipped in place when the light source is blocked. Inother embodiments, the barrel flange sensor 700 may be comprised of adifferent sensor than those described above. The barrel flange sensor700 may be caused generate an alarm in the event that other sensors,such as the plunger clamp jaws position sensor 588 (mentioned above) orthe syringe barrel holder linear position sensor 1540 (see FIG. 66),detect a syringe 504 in place of the syringe pump assembly 501 when thebarrel flange sensor 700 does not detect a syringe 504 in place and aninitiation of a therapy is attempted.

FIG. 63 shows an embodiment of part of the syringe barrel holder 518. Asshown in FIG. 63, the syringe barrel holder 518 comprises a syringebarrel holder housing 1500. In the example embodiment, the syringebarrel holder housing 1500 has a planate base plate 1502. The planatebase plate 1502 comprises a syringe barrel holder housing member 1504 atits left end (relative to FIG. 63). The syringe barrel holder housingmember 1504 projects off the bottom of the syringe barrel holder housing1500 at an angle substantially perpendicular to the plane of the planatebase plate 1502. The syringe barrel holder housing member 1504 mayextend substantially perpendicularly from the entire length of the leftend of the planate base plate 1502. In some embodiments, the syringebarrel holder housing member 1504 may take the form of a rectangularprism. In the example embodiment shown in FIG. 63, the syringe barrelholder housing member 1504 has a form close to a rectangular prism, butthe bottom edges of the syringe barrel holder housing member 1504 havebeen rounded off.

As shown in FIG. 63, the planate base plate 1502 may have a base plateslot 1506 cut into it. The base plate slot 1506 may be cut into theplanate base plate 1502 from the left edge (relative to FIG. 63) of theplanate base plate 1502. The base plate slot 1506 may extend into theplanate base plate 1502 at an angle substantially perpendicular to theleft edge of the planate base plate 1502. The base plate slot does notextend all the way across the planate base plate 1502 and stops short ofthe right edge.

On the flanks of the base plate slot 1506, one or more syringe barrelholder housing posts 1508 may be disposed. In the example embodimentshown in FIG. 63, four syringe barrel holder housing posts 1508 flankthe base plate slot 1506. The four syringe barrel holder housing posts1508 are divided up such that there are two syringe barrel holderhousing posts 1508 on each flank of the base plate slot 1506. Thesyringe barrel holder housing posts 1508 extend substantiallyperpendicularly from the top face of the planate base plate 1502 towardthe top of the page. The syringe barrel holder housing posts 1508 in theexample embodiment shown in FIG. 63 have the form of rectangular prisms.In alternate embodiment, the syringe barrel housing posts 1508 may becylindrical or have any other suitable shape.

The planate base plate 1502 may also comprise one or more syringe barrelholder housing bodies 1510. In the example embodiment shown in FIG. 63,there are two syringe barrel holder housing bodies 1510. The syringebarrel holder housing bodies 1510 projects perpendicularly from the topof the planate base plate 1502 toward the top of the page. The syringebarrel holder housing bodies 1510 have the form of rectangular prisms.As shown, the syringe barrel holder housing bodies 1510 may overhang theright edge of the planate base plate 1502. The syringe barrel holderhousing bodies 1510 may comprise one side which is flush with the frontedge or back edge (relative to FIG. 63) of the planate base plate 1502.

In some embodiments, the syringe barrel holder housing 1500 may comprisea “T” shaped member 1512. In the example embodiment shown in FIG. 63,the stem portion of the “T” shaped member extends toward the right ofthe page from the right edge of the planate base plate 1502. The “T”shaped member 1512 may extend on a plane substantially parallel to theplane of the planate base plate 1502. In the example embodiment, the “T”shaped member 1512 projects from roughly the center of the right edge ofthe planate base plate 1502. The cross portion of the “T” shaped member1512 is roughly parallel with the right edge of the planate base plate1502. The cross portion of the “T” shaped member 1512 overhangs the stemequally on both sides of the stem.

As shown in FIG. 63, syringe barrel holder guide rails 1514 may extendsubstantially perpendicularly from the right face of the syringe barrelholder housing member 1504 and into the left faces of the overhangingcross portions of the “T” shaped member 1512. The syringe barrel holderguide rails 1514 may extend substantially parallel to each other. In theexample embodiment shown in FIG. 63, a coil spring 1516 surrounds eachsyringe barrel holder guide rail 1514. One end of each coil spring 1516may abut the left face of the cross portion of the “T” shaped member1512. In the example embodiment, the coil springs 1516 are compressionsprings. In alternate embodiments, other bias members or bias memberarrangements may be utilized.

As shown in the embodiment in FIG. 63, a syringe barrel holder printedcircuit board (PCB) 1518 may be held in place on the syringe barrelholder housing posts 1508. The syringe barrel holder PCB may be coupledin place on the syringe barrel holder housing posts 1508 by any suitablemeans. In the example embodiment shown in FIG. 63, the syringe barrelholder PCB is coupled to the syringe barrel holder housing posts 1508 byscrews.

FIG. 64 shows an embodiment of part of the syringe barrel holder 518. Inthe embodiment shown in FIG. 64, the syringe barrel holder PCB 1518shown in FIG. 63 has been removed. As shown in FIG. 64 the base plateslot 1506 may extend down into the syringe barrel holder housing member1504. The base plate slot 1508 may comprise a base plate notch catch1520. In embodiments where the base plate slot 1508 comprises a baseplate notch catch 1520 the base plate notch catch 1520 may be a void inthe planate base plate 1502 of the syringe barrel holder housing 1500.In the example embodiment, the void of the base plate notch catch 1520extends out from the right end section of the base plate slot 1508 at anangle substantially perpendicular to the side of the base plate slot1508.

The syringe barrel holder 518 may also comprise a syringe barrel holderarm rod 1522. In the example embodiment shown in FIG. 64, the syringebarrel holder arm rod 1522 extends through an appropriately sized borein the approximate center of the “T” shaped member 1512 (only the stemof the “T” shaped member 1512 is visible in FIG. 64). The syringe barrelholder arm rod 1522 may be movably coupled to the syringe barrel holder518. In embodiments where the syringe barrel holder arm rod 1522 ismovably coupled to the syringe barrel holder 518, the syringe barrelholder arm rod 1522 may move along a direction parallel to the edges ofthe stem of the “T” shaped member 1512. In the example embodiment inFIG. 64, the syringe barrel holder arm rod 1522 is able to slide alongthe bore in the “T” shaped member 1512 and uses the bore in the “T”shaped member 1512 as a linear motion bearing. In the exampleembodiment, the syringe barrel holder arm rod 1522 is longer than thelength of the stem of the “T” shaped member 1512.

As shown in FIG. 64, one end of the syringe barrel holder arm rod 1522may comprise a collar which may be a “U” shaped member 1524. The “U”shaped member 1524 may be fixedly coupled to the syringe barrel holderarm rod 1522. In the example embodiment, the bottom span of the “U”shaped member 1524 is thicker than the uprights of the “U” shaped member1524. The thick bottom span of the “U” shaped member 1524 comprises ahole which allows the “U” shaped member 1524 to be coupled onto thesyringe barrel holder arm rod 1522 when the syringe barrel holder 518 isassembled. In the example embodiment, the uprights of the “U” shapedmember 1524 extend up through the base plate slot 1506 and aresubstantially flush with the plane of the top face of the planate baseplate 1502. The uprights of the “U” shaped member 1524 may constrain thesyringe barrel holder arm rod 1522 from rotation since any rotation isblocked by the uprights of the “U” shaped member 1524 abutting the edgesof the base plate slot 1506.

In the example embodiment shown in FIG. 64, the syringe barrel holder518 comprises a bias bar 1526. The bias bar 1526 in the exampleembodiment, is roughly rectangular in shape. The bias bar 1526 maycomprise two holes which allow the bias bar 1526 to be placed on thesyringe barrel holder guide rails 1514. The bias bar 1526 may be capableof guided movement along the axial direction of the syringe barrelholder guide rails 1514. In the example embodiment, the end of the coilsprings 1516 on the syringe barrel holder guide rails 1514 not abuttingthe cross portion of the “T” shaped member 1512 abuts the front face ofthe bias bar 1526. In the example embodiment shown in FIG. 64 themaximum distance between the face of the bias bar 1526 which one end ofthe coil springs 1516 abut and the face of the “T” shaped member 1512which the other end of the coil springs 1516 abut is shorter than theuncompressed length of the coil springs 1516. This ensures that the biasbar 1526 will always be biased toward the position shown in FIG. 64.

As shown in FIG. 64, the bias bar 1526 may comprise a cutout whichallows the bias bar 1526 to fit around at least part of the syringebarrel holder arm rod 1522. The “U” shaped member 1524 may abut the faceof the bias bar 1526 opposite the side which the coil springs 1516 abut.In such embodiments, the action of the coil springs 1516 biasing thebias bar 1526 toward the position depicted in FIG. 64, additionallybiases the syringe barrel holder arm rod 1522 to the position depictedin FIG. 64.

In the example embodiment in FIG. 65, the syringe barrel holder 518 isshown in the fully open position. To move the syringe barrel holder 518to the open fully open position, a user may grasp the syringe barrelholder grip 1528. In the example embodiment shown in FIG. 65, thesyringe barrel holder grip 1528 is a projection which extends from thebarrel contacting structure 1530 of the syringe barrel holder 518 whichis fixedly coupled to the syringe barrel holder arm rod 1522. Aftergrasping the syringe barrel holder grip 1528, a user may pull thesyringe barrel holder arm rod 1522 away from the syringe barrel holderhousing 1500. This action causes the “U” shaped member 1524 which isfixedly attached to the syringe barrel holder arm rod 1522 to move aswell. Since the “U” shaped member 1524 may not pass through the bias bar1526, the bias bar 1526 moves with the “U” shaped member 1524 andsyringe barrel holder arm rod 1522. As the bias bar 1526 moves along thesyringe barrel holder guide rails 1514, the coil springs becomecompressed such that if a user releases the syringe barrel holder grip1528, the restoring force of the coil springs will automatically returnthe bias bar 1526, “U” shaped member 1524, and syringe barrel holder armrod 1522 to the positions shown in FIG. 64.

To hold the syringe barrel holder 518 in the fully open position againstthe bias of the coil springs 1516, the syringe barrel holder 518 may belocked in the open position. As shown, the syringe barrel holder 518 maybe locked in the open position by rotating the syringe barrel holder armrod 1522 and all parts fixedly coupled to the syringe barrel holder armrod 1522. In FIG. 65, the syringe barrel holder arm rod 1522 has beenrotated substantially 90° such that the bottom span of the “U” shapedmember 1524 is disposed within the base plate notch catch 1520. When the“U” shaped member is rotated into the base plate notch catch 1520, therestoring force of the coil springs 1516 is not capable of returning thesyringe barrel holder 518 to the position shown in FIG. 64 becausetravel of the “U” shaped member 1524 is blocked by the base plate notchcatch 1520.

After rotating the syringe barrel holder arm rod 1522 such that thesyringe barrel holder 518 is locked in the open position, a user mayrelease the syringe barrel holder grip 1528 to grasp a syringe 504 (notshown) and put it in place. As mentioned above, the syringe barrelholder 518 will remain in the fully open position. A user may thenrotate the syringe barrel holder arm rod 1522 90° back to its original,unlocked position and allow the syringe barrel holder 518 to hold thesyringe 504 in place.

Referring back to FIG. 31 the syringe barrel holder 518 is shown fullyopen and rotated into the locked position. In the fully open position,the syringe barrel contacting structure 1530 and syringe barrel holdergrip 1528 are at their furthest possible distance from the syringe seat506 of the syringe pump assembly 501. In some embodiments, this distancemay be substantially larger than the diameter of the largest syringe 504which may be accepted by the syringe pump 500. In FIG. 31, a syringe 504has been put in place against the syringe seat 506 while the syringebarrel holder 518 has be locked in the open position. In FIG. 32, thesyringe barrel holder has been rotated out of the locked position andhas been allowed to automatically adjust to the size of the syringebarrel 540. As mentioned in the discussion of FIG. 65, this automaticadjustment is a result of the restoring force of the coil springs 1516automatically pushing the bias bar 1526, “U” shaped member 1524, and thesyringe barrel holder arm rod 1522 toward the position depicted in FIG.64.

In FIG. 66, an example embodiment of the syringe barrel holder 518 isshown. In the embodiment depicted in FIG. 66 the syringe barrel holderPCB 1518 is shown as transparent. The syringe barrel holder PCB 1518 maycomprise one or a number of syringe barrel holder linear positionsensors 1540. In the example embodiment, there are three syringe barrelholder linear position sensors 1540. The syringe barrel holder linearposition sensors 1518 may be used to determine the size of the syringe504 (not shown) which the syringe barrel holder 518 is holding in place.

In some embodiments, there may only be a single syringe barrel holderlinear position sensor 1540. In such embodiments, the syringe barrelholder linear position sensor 1540 may be a linear potentiometer. Inembodiments where the syringe barrel holder linear position sensor 1540is a linear potentiometer, the syringe barrel holder linear positionsensor 1540 may comprise a barrel sizing wiper 1542 which may slideacross the resistive element of the potentiometer with movement of thesyringe barrel holder arm rod 1522. When a syringe 504 (not shown) isheld by the syringe barrel holder 518, the size of the syringe 504 (notshown) will determine the position of the barrel sizing wiper 1542 alongthe linear potentiometer type syringe barrel holder linear positionsensor 1540. Since the location of the wiper 1542 will vary theresistance measured by the linear position sensor 1540, the resistancemeasured may be used to establish information (size, volume, brand,etc.) about the syringe 504 (not shown) being used. In some embodiments,the resistance measurement may be referenced with a database orresistance measurements which would be expected from different syringes504 to determine information about the syringe 504. The resistancemeasurement may additionally be used to determine whether a syringe 504is properly held by the syringe barrel holder 518. For example, if theresistance measurement indicates that the syringe barrel holder 518 isin the fully open position (as it is in FIG. 66), an alarm may begenerated and a therapy may not be initiated.

In some embodiments, including the example embodiment shown in FIG. 66,the syringe barrel holder linear position sensors 1540 may be magneticlinear position sensors. Any suitable magnetic linear position sensormay be used for the syringe barrel holder linear position sensor 1540.The syringe barrel holder linear position sensors 1540 may be the sametype of sensors as the sliding block assembly linear position sensors1050. An example of a suitable magnetic linear position sensor is the“AS5410 Absolute Linear 3D Hall Encoder” available fromAustriamicrosystems of Austria. The syringe barrel holder linearposition sensors 1540 gather their positional data from a syringe barrelholder magnet 1544 placed at a suitable distance from the syringe barrelholder linear position sensors 1540. In the example embodiment shown inFIG. 66, the syringe barrel holder magnet 1544 rests on the bottom spanof the “U” shaped member 1524 between the two uprights of the “U” shapedmember 1524. The absolute location of the syringe barrel holder magnetmay be measured by the syringe barrel holder linear position sensors1540. Since the measured absolute location of the syringe barrel holdermagnet 1544 may vary depending on the syringe 504 (not shown) being heldby the syringe barrel holder 518, the absolute location of the syringebarrel holder magnet 1544 can be used to determine specific information(for example, size, volume, brand, etc.) about the syringe 504 (notshown) being held. In some embodiments, the absolute location of thesyringe barrel holder magnet 1544 may be referenced with a database todetermine information about the syringe 504 being utilized. In suchembodiments, the database may be a database of absolute locations whichwould be expected with different syringes 504. The absolute positionmeasurement may also be used to determine whether a syringe 504 iscorrectly held in place by the syringe barrel holder 518. For example,if the absolute position measurement indicates that the syringe barrelholder 518 is in the fully open position (as it is in FIG. 66), an alarmmay be generated and a therapy may not be initiated.

In some embodiments, the data gathered by the syringe barrel holderlinear position sensor 1540 may be compared to data gathered by othersensors to make a more informed decision on the specific syringe 504being used. For example, in embodiments where a plunger clamp jawsposition sensor 588 may make a determination on the type of syringe 504being used (see discussion of FIG. 37) the data from the plunger clampjaws position sensor 588 and linear position sensor 1540 may becompared. If the data gathered by the syringe barrel holder linearposition sensor 1540 does not correlate with data gathered by othersensors, an alarm may be generated.

In some embodiments, data from the plunger clamp jaws position sensor588 may be first referenced against a syringe 504 database to narrowdown acceptable syringe barrel 540 measurements. In some embodiments,data from the syringe barrel holder linear position sensor may bereferenced against a syringe 504 database to set a range of acceptableplunger flange 548 measurements.

FIG. 67 shows a basic example of part of an alternative linear positionsensor. The part of the alternative linear position sensor in FIG. 67 isa line stretcher 1600. In the example embodiment, the line stretcher1600 comprises a stationary portion and a moving portion. The stationaryportion comprises an FR-4 PCB substrate 1602. On the substrate 1602there are two microstrips 1604. As shown, the microstrips 1604 extendparallel to each other. The microstrips 1604 act as transmission linesfor a signal at a known frequency. The microstrips 1604 do not allow thesignal to propagate into the ambient environment. The width of themicrostrips 1604 is chosen so that it is suitable for the desiredimpedance. In an example embodiment, the desired impedance is 50Ω.

The moving portion in the example embodiment comprises a moving portionFR-4 PCB substrate 1606. As shown, the moving portion FR-4 PCB substratecomprises a moving portion microstrip 1608. The moving portionmicrostrip 1608 may be substantially “U” shaped. The uprights of the “U”shaped moving portion microstrip 1608 extend parallel to each other andare spaced such that when the line stretcher 1600 is assembled they maycontact the two microstrips 1604 on the stationary portion. The moveableportion microstrips 1608 have a width chosen so that it is suitable fordesired amount of impedance (50Ω in the example embodiment). The bottomspan of the “U” shaped movable portion microstrip 1608 connects the twouprights of the “U” shaped movable portion microstrip 1608 and issubstantially perpendicular to the two uprights. When fully assembled,the bottom span of the “U” shaped movable portion microstrip 1604 formsa bridge between the two microstrips 1604 on the stationary portion ofthe line stretcher 1600. Any signal sent through one of the microstrips1604 on the stationary portion may cross via the moving portionmicrostrip 1608 to the other microstrip 1604 on the stationary portion.By sliding the moving portion along the direction of extension of thestationary portion microstrips 1604 the signal must travel a greater orshorter distance before crossing from one stationary portion microstrip1604 to the other. By manipulating the amount of travel of the signal, auser may predictably create a phase change of the signal. To reduce wearon the metal microstrips 1604 and 1608 a thin sheet of insulation 1609may be placed between the microstrips 1604 and 1608, creating acapacitive coupling.

FIG. 68 shows an example of the line stretcher 1600 being incorporatedinto a phase change detector 1610. As shown, the phase change detector1610 comprises a signal source shown as “RF SOURCE” in the example shownin FIG. 68. The source signal in the example shown in FIG. 68 travelsfrom the “RF SOURCE” to a “POWER SPLITTER”. The “POWER SPLITTER” splitsthe signal, keeping the two output signals in a constant phaserelationship with one another. One of the signals travels directly to a“FREQUENCY MIXER”. The other signal is delayed before it is allowed toreach the “FREQUENCY MIXER”. In FIG. 68, the signal is delayed by theline stretcher 1600 (see FIG. 67). Delaying the signal causes thedelayed signal to be predictably out of phase with the non-delayedsignal which travels directly to the “FREQUENCY MIXER”. The delayedsignal travels from line stretcher 1600 to the “FREQUENCY MIXER”. In theexample embodiment shown in FIG. 68 the “FREQUENCY MIXER” is a doublebalanced frequency mixer. As is well known in the art, two identicalfrequency, constant-amplitude signals sent to a mixer will result in aDC output which is proportional to the phase difference between the twosignals.

FIG. 69 depicts a slightly different embodiment of the phase changedetector 1610. In FIG. 69 the delay means is not a line stretcher 1600such as the one described in FIG. 67. The delay means is a variable openor short. As the object whose linear position is to be measured linearlydisplaces, the short or open's location on a transmission line may becaused to move proportionally. As shown, the signal travels through a“DIRECTIONAL COUPLER” which may be any suitable directional coupler. Asone of the two signals the signal enters the “DIRECTIONAL COUPLER” fromthe “POWER SPLITTER” the signal is sent out of another port of the“DIRECTIONAL COUPLER to an open or short. The open or short causes thesignal to reflect back to the port from which it traveled to reach theopen or short. The signal reflected back into the port is then directedby the “DIRECTIONAL COUPLER” to travel into the “FREQUENCY MIXER”. Thedelay of the signal caused by the distance traveled to and from thepoint of reflection causes a phase shift in the signal. The amount ofphase shift of the signal is dependent on the distance from the portfrom which the signal exits the “DIRECTIONAL COUPLER” to the open orshort. This distance may be caused to change in consequence to movementof the object whose linear position is to be measured. The second signaloutput of the “POWER SPLITTER” travels directly to the “FREQUENCYMIXER”. As is well known in the art, two identical frequency,constant-amplitude signals sent to a mixer will result in a DC outputwhich is proportional to the phase difference between the two signals.

As shown in FIG. 70, the “DIRECTIONAL COUPLER” may be replaced withanother piece of equipment such as a circulator. The phase changedetector 1610 in FIG. 70 functions very similarly to the phase changedetector 1610 in FIG. 69. One signal from the power splitter travelsdirectly to the “FREQUENCY MIXER”. The other signal is delayed. Thedelay is caused in the same manner as described above. Instead of usinga “DIRECTIONAL COUPLER”, however, a “CIRCULATOR” may be used to directthe signal. As the signal enters the “CIRCULATOR” at port 1 the signalis circulated to port 2. The signal travels from port 2 to the short oropen and is reflected back into port 2. The reflected, phase shiftedsignal entering port 2 of the “CIRCULATOR” is circulated to port 3. Thesignal exits port 3 and travels to the “FREQUENCY MIXER” As is wellknown in the art, two identical frequency, constant-amplitude signalssent to a mixer will result in a DC output which is proportional to thephase difference between the two signals. Since the phase difference isdependent on the distance of the short or open from port 2 of the“CIRCULATOR” and the distances varies in proportion to the location ofthe object whose linear location is to be found the DC output of themixer may be used to determine the objects location.

In some embodiments, the phase change detector 1610 may be used tosubstitute for the syringe barrel holder linear position sensors 1540(see FIG. 66) or the sliding block magnetic linear position sensors 1054(see FIG. 57). In some embodiments, only one of the syringe barrelholder linear position sensors 1540 or the sliding block magnetic linearposition sensors 1054 may be substituted for with the phase changedetector 1610. In some embodiments, a phase change detector 1610 may beused in conjunction with one or both the syringe barrel holder linearposition sensors 1540 or the sliding block magnetic linear positionsensors 1054 and function as a cross check or backup.

In embodiments where the sliding block assembly linear position sensor1054 (see FIG. 57) is substituted for with a phase change detector 1610,the phase change detector 1610 may be used to detect the position of thesliding block assembly 800 along the lead screw 850 (see FIG. 57). Ifthe phase shift detector 1610 uses a line stretcher 1600 (see FIG. 67)the moveable portion of the line stretcher 1600 may be caused to movealong the stationary portion of the line stretcher 1600 with movement ofthe sliding block assembly 800 along the lead screw 850. In turn thiswould cause the degree of phase change to reflect the position of thesliding block assembly 800 on the lead screw 850. Consequently, the DCoutput voltage of the mixer (see FIG. 68) may be used to determine theposition of the sliding block assembly 800. The positional datagenerated by the phase change detector 1610 may be used in the samemanner as described above in relation to the prior discussion of slidingblock assembly 800 linear position sensing.

In embodiments where the phase change detector 1610 uses a variableshort or open (see FIG. 69 and FIG. 70), movement of the sliding blockassembly 800 along the lead screw 850 may cause the short or open tochange its location along the transmission line. In turn this wouldcause the degree of phase change to specify the position of the slidingblock assembly 800 along the lead screw 850. Consequently, the DC outputvoltage of the mixer (see FIG. 69 and FIG. 70) may be used to determinethe position of the sliding block assembly 800.

In embodiments where the syringe barrel holder linear position sensors1540 (see FIG. 66) is substituted for by the phase change detector 1610,the phase change detector 1610 may be used to may be used to determinethe size of the syringe 504 (see FIG. 28). If the phase change detector1610 uses a line stretcher 1600 (see FIG. 67) the moveable portion ofthe line stretcher 1600 may be caused to move along the stationaryportion of the line stretcher 1600 with movement of the syringe barrelholder arm rod 1522. In turn this would cause the degree of phase changeto reflect the position of the syringe barrel holder arm rod 1522. Sincethe position of the syringe barrel holder arm rod 1522 is dependent uponvarious characteristics of the syringe 504, the DC output voltage of themixer (see FIG. 68) may be used to determine the position of the of thesyringe barrel holder arm rod 1522 and therefore a number ofcharacteristics of the syringe 504.

In embodiments where the phase change detector 1610 uses a variableshort or open (see FIG. 69 and FIG. 70), movement of the syringe barrelholder arm rod 1522 may cause the short or open to change its locationalong a transmission line. In turn this would cause the degree of phasechange to specify the position of the syringe barrel holder arm rod1522. Since the position of the syringe barrel holder arm rod 1522 isdependent upon various characteristics of the syringe 504, the DC outputvoltage of the mixer (see FIG. 69 and FIG. 70) may be used to determinethe position of the syringe barrel holder arm rod 1522 and therefore anumber of characteristics of the syringe 504. The positional datagenerated by the phase change detector 1610 may be used in the samemanner as described above in relation to the prior discussion of syringebarrel holder linear position sensing.

An example embodiment of the graphic user interface (hereafter GUI) 3300is shown in FIG. 71. The GUI 3300 enables a user to modify the way thatan agent may be infused by the syringe pump 500 by customizing variousprogramming options. Though the following discussion mostly details theuse of the GUI 3300 with the syringe pump 500, it should be appreciatedthat the GUI 3300 may be used with other pumps, including the otherpumps mentioned in this specification. For example, the GUI 3300 may beused with the pump 201, 202, or 203 (as shown in FIG. 71) detailed inthe discussion of FIGS. 2-9. For purposes of example, the GUI 3300detailed as follows uses a screen 3204 which is a touch screen display514 (see FIG. 28) as a means of interaction with a user. In otherembodiments, the means of interaction with a user may be different. Forinstance, alternate embodiments may comprise user depressible buttons orrotatable dials, audible commands, etc. In other embodiments, the screen3204 may be any electronic visual display such as a, liquid crystaldisplay, L.E.D. display, plasma display, etc.

As detailed in the preceding paragraph, the GUI 3300 is displayed on thedisplay 514 of the syringe pump 500. Each syringe pump 500 may have itsown individual screen 3204. In arrangements where there are multiplesyringe pumps 500 or a syringe pump 500 and one or more other pumps, theGUI 3300 may be used to control multiple pumps. Only the master pump mayrequire a screen 3204. As shown in FIG. 71, the pump 203 is seated in aZ-frame 3207. As shown, the GUI 3300 may display a number of interfacefields 3250. The interface fields 3250 may display various informationabout the pump 203, infusion status, and/or the medication, etc. In someembodiments, the interface fields 3250 on the GUI 3300 may be touched,tapped, etc. to navigate to different menus, expand an interface field3250, input data, and the like. The interface fields 3250 displayed onthe GUI 3300 may change from menu to menu.

The GUI 3300 may also have a number of virtual buttons. In thenon-limiting example embodiment in FIG. 71 the display has a virtualpower button 3260, a virtual start button 3262, and a virtual stopbutton 3264. The virtual power button 3260 may turn the syringe pump 500on or off. The virtual start button 3262 may start an infusion. Thevirtual stop button 3264 may pause or stop an infusion. The virtualbuttons may be activated by a user's touch, tap, double tap, or thelike. Different menus of the GUI 3300 may comprise other virtualbuttons. The virtual buttons may be skeuomorphic to make their functionsmore immediately understandable or recognizable. For example, thevirtual stop button 3264 may resemble a stop sign as shown in FIG. 71.In alternate embodiments, the names, shapes, functions, number, etc. ofthe virtual buttons may differ.

As shown in the example embodiment in FIG. 72, the interface fields 3250of the GUI 3300 (see FIG. 71) may display a number of differentprogramming parameter input fields. For the GUI 3300 to display theparameter input fields, a user may be required to navigate through oneor a number of menus. Additionally, it may be necessary for the user toenter a password before the user may manipulate any of the parameterinput fields.

In FIG. 72, a medication parameter input field 3302, in container drugamount parameter input field 3304, total volume in container parameterinput field 3306, concentration parameter input field 3308, doseparameter input field 3310, volume flow rate (hereafter abbreviated asrate) parameter input field 3312, volume to be infused (hereafter VTBI)parameter input field 3314, and time parameter input field 3316 aredisplayed. The parameters, number of parameters, names of theparameters, etc. may differ in alternate embodiments. In the exampleembodiment, the parameter input fields are graphically displayed boxeswhich are substantially rectangular with rounded corners. In otherembodiments, the shape and size of the parameter input fields maydiffer.

In the example embodiment, the GUI 3300 is designed to be intuitive andflexible. A user may choose to populate a combination of parameter inputfields which are simplest or most convenient for the user. In someembodiments, the parameter input fields left vacant by the user may becalculated automatically and displayed by the GUI 3300 as long as thevacant fields do not operate independently of populated parameter inputfields and enough information can be gleaned from the populated fieldsto calculate the vacant field or fields. Throughout FIGS. 72-76, fieldsdependent upon on another are tied together by curved double-tippedarrows.

The medication parameter input field 3302 may be the parameter inputfield in which a user sets the type of infusate agent to be infused. Inthe example embodiment, the medication parameter input field 3302 hasbeen populated and the infusate agent has been defined as “0.9% NORMALSALINE”. As shown, after the specific infusate has been set, the GUI3300 may populate the medication parameter input field 3302 bydisplaying the name of the specific infusate in the medication parameterinput field 3302.

To set the specific infusate agent to be infused, a user may touch themedication parameter input field 3302 on the GUI 3300. In someembodiments, this may cull up a list of different possible infusates.The user may browse through the list until the desired infusate islocated. In other embodiments, touching the in medication parameterinput field 3302 may cull up a virtual keyboard. The user may then typethe correct infusate on the virtual keyboard. In some embodiments, theuser may only need to type only a few letters of the infusate on thevirtual keyboard before the GUI 3300 displays a number of suggestions.For example, after typing “NORE” the GUI 3300 may suggest“NOREPINEPHRINE”. After locating the correct infusate, the user may berequired to perform an action such as, but not limited to, tapping,double tapping, or touching and dragging the infusate. After therequired action has been completed by the user, the infusate may bedisplayed by the GUI 3300 in the medication parameter input field 3302.For another detailed description of another example means of infusateselection see FIG. 82.

In the example embodiment in FIG. 72, the parameter input fields havebeen arranged by a user to perform a volume based infusion (for instancemL, mL/hr, etc.). Consequentially, the in container drug amountparameter input field 3304 and total volume in container parameter inputfield 3306 have been left unpopulated. The concentration parameter inputfield 3308 and dose parameter input field 3310 have also been leftunpopulated. In some embodiments, the in container drug amount parameterinput field 3304, total volume in container parameter input field 3306,concentration parameter input field 3308, and dose parameter input field3310 may be locked, grayed out, or not displayed on the GUI 3300 whensuch an infusion has been selected. The in container drug amountparameter input field 3304, total volume in container parameter inputfield 3306, concentration parameter input field 3308, and dose parameterinput field 3310 will be further elaborated upon in subsequentparagraphs.

When the GUI 3300 is being used to program a volume base infusion, therate parameter input field 3312, VTBI parameter input field 3314, andtime parameter input field 3316 do not operate independent of oneanother. A user may only be required to define any two of the rateparameter input field 3312, VTBI parameter input field 3314, and timeparameter input field 3316. The two parameters defined by a user may bethe most convenient parameters for a user to set. The parameter leftvacant by the user may be calculated automatically and displayed by theGUI 3300. For instance, if a user populates the rate parameter inputfield 3312 with a value of 125 mL/hr (as shown), and populates the VTBIparameter input field 3314 with a value of 1000 mL (as shown) the timeparameter input field 3316 value may be calculated by dividing the valuein the VTBI parameter input field 3314 by the value in the rateparameter input field 3312. In the example embodiment shown in FIG. 72,the quotient of the above calculation, 8 hrs and 0 min, is correctlypopulated by the GUI 3300 into the time parameter input field 3316.

For a user to populate the rate parameter input field 3312, VTBIparameter input field 3314, and time parameter input field 3316 the usermay touch or tap the desired parameter input field on the GUI 3300. Insome embodiments, this may cull up a number pad with a range or number,such as 0-9 displayed as individual selectable virtual buttons. A usermay be required to input the parameter by individually tapping, doubletapping, touching and dragging, etc. the desired numbers. Once thedesired value has been input by a user, a user may be required to tap,double tap, etc. a virtual “confirm”, “enter”, etc. button to populatethe field. For another detailed description of another example way ofdefining numerical values see FIG. 82.

FIG. 73 shows a scenario in which the infusion parameters beingprogrammed are not those of a volume based infusion. In FIG. 73, theinfusion profile is that of a continuous volume/time dose rate. In theexample embodiment shown in FIG. 73, all of the parameter input fieldshave been populated. As shown, the medication parameter input field 3302on the GUI 3300 has been populated with “HEPARIN” as the definedinfusate. As shown, the in container drug amount parameter input field3304, total volume in container input field 3306, and concentrationparameter input field 3308 are populated in FIG. 73. Additionally, sincea volume/time infusion is being programmed the dose parameter inputfield 3310 shown in FIG. 72 has been replaced with a dose rate parameterinput field 3318.

The in container drug amount parameter input field 3304 is a two partfield in the example embodiment shown in FIG. 73. In the exampleembodiment in FIG. 73 the left field of the in container drug amountparameter input field 3304 is a field which may be populated with anumeric value. The numeric value may defined by the user in the samemanner as a user may define values in the rate parameter input field3312, VTBI parameter input field 3314, and time parameter input field3316. In the example embodiment shown in FIG. 73, the numeric valuedisplayed by the GUI 3300 in the in left field of the in container drugamount parameter input field 3304 is “25,000”.

The parameter defined by the right field of the in container drug amountparameter input field 3304 is the unit of measure. To define the rightof the in container drug amount parameter input field 3304, a user maytouch the in container drug amount parameter input field 3304 on the GUI3300. In some embodiments, this may cull up a list of acceptablepossible units of measure. In such embodiments, the desired unit ofmeasure may be defined by a user in the same manner as a user may definethe correct infusate. In other embodiments, touching the in containerdrug amount parameter input field 3304 may cull up a virtual keyboard.The user may then type the correct unit of measure on the virtualkeyboard. In some embodiments the user may be required to tap, doubletap, etc. a virtual “confirm”, “enter”, etc. button to populate the leftfield of the in container drug amount parameter input field 3304.

The total volume in container parameter input field 3306 may bepopulated by a numeric value which defines the total volume of acontainer. In some embodiments, the GUI 3300 may automatically populatethe total volume in container parameter input field 3306 based on datagenerated by one or more sensors. In other embodiments, the total volumein container parameter input field 3306 may be manually input by a user.The numeric value may defined by the user in the same manner as a usermay define values in the rate parameter input field 3312, VTBI parameterinput field 3314, and time parameter input field 3316. In the exampleembodiment shown in FIG. 73 the total volume in container parameterinput field 3306 has been populated with the value “250” mL. The totalvolume in container parameter input field 3306 may be restricted to aunit of measure such as mL as shown.

The concentration parameter input field 3308 is a two part field similarto the in container drug amount parameter input field 3304. In theexample embodiment in FIG. 73 the left field of the concentrationparameter input field 3308 is a field which may be populated with anumeric value. The numeric value may defined by the user in the samemanner as a user may define values in the rate parameter input field3312, VTBI parameter input field 3314, and time parameter input field3316. In the example embodiment shown in FIG. 73, the numeric valuedisplayed by the GUI 3300 in the in left field of the concentrationparameter input field 3308 is “100”.

The parameter defined by the right field of the concentration parameterinput field 3308 is a unit of measure/volume. To define the right fieldof the concentration parameter input field 3308, a user may touch theconcentration parameter input field 3308 on the GUI 3300. In someembodiments, this may cull up a list of acceptable possible units ofmeasure. In such embodiments, the desired unit of measure may be definedby a user in the same manner as a user may define the correct infusate.In other embodiments, touching the concentration parameter input field3308 may cull up a virtual keyboard. The user may then type the correctunit of measure on the virtual keyboard. In some embodiments the usermay be required to tap, double tap, etc. a virtual “confirm”, “enter”,etc. button to store the selection and move on to a list of acceptablevolume measurements. The desired volume measurement may be defined by auser in the same manner as a user may define the correct infusate. Inthe example embodiment shown in FIG. 73 the right field of theconcentration parameter input field 3308 is populated with the unit ofmeasure/volume “UNITS/mL”.

The in container drug amount parameter input field 3304, total volume incontainer input field 3306, and concentration parameter input field 3308are not independent of one another. As such, a user may only be requiredto define any two of the in container drug amount parameter input field3304, total volume in container input field 3306, and concentrationparameter input field 3308. For instance, if a user were to populate theconcentration parameter input field 3308 and the total volume incontainer parameter input field 3306, the in container drug amountparameter input field may be automatically calculated and populated onthe GUI 3300.

Since the GUI 3300 in FIG. 73 is being programmed for a continuousvolume/time dose, the dose rate parameter input field 3318 has beenpopulated. The user may define the rate at which the infusate is infusedby populating the dose rate parameter input field 3318. In the exampleembodiment in FIG. 73, the dose rate parameter input field 3318 is a twopart field similar to the in container drug amount parameter input field3304 and concentration parameter input field 3308 described above. Anumeric value may defined in the left field of the dose rate parameterinput field 3318 by the user in the same manner as a user may definevalues in the rate parameter input field 3312. In the example embodimentin FIG. 73, the left field of the dose rate parameter input field 3318has been populated with the value “1000”.

The right field of the dose rate parameter input field 3318 may define aunit of measure/time. To define the right field of the dose rateparameter input field 3318, a user may touch the dose rate parameterinput field 3318 on the GUI 3300. In some embodiments, this may cull upa list of acceptable possible units of measure. In such embodiments, thedesired unit of measure may be defined by a user in the same manner as auser may define the correct infusate. In other embodiments, touching thedose rate parameter input field 3304 may cull up a virtual keyboard. Theuser may then type the correct unit of measure on the virtual keyboard.In some embodiments the user may be required to tap, double tap, etc. avirtual “confirm”, “enter”, etc. button to store the selection and moveon to a list of acceptable time measurements. The desired timemeasurement may be defined by a user in the same manner as a user maydefine the correct infusate. In the example embodiment shown in FIG. 73the right field of the dose rate parameter input field 3318 is populatedwith the unit of measure/time “UNITS/hr”.

In the example embodiment, the dose rate parameter input field 3318 andthe rate parameter input field 3312 are not independent of one another.After a user populates the dose rate parameter input field 3318 or therate parameter input field 3312, the parameter input field left vacantby the user may be calculated automatically and displayed by the GUI3300 as long as the concentration parameter input field 3308 has beendefined. In the example embodiment shown in FIG. 73, the rate parameterinput field 3312 has been populated with an infusate flow rate of “10mL/hr”. The dose rate parameter input field 3318 has been populated with“1000” “UNITS/hr”.

In the example embodiment shown in FIG. 73 the VTBI parameter inputfield 3314 and time parameter input field 3316 have also been populated.The VTBI parameter input field 3314 and time parameter input field 3316may be populated by a user in the same manner described in relation toFIG. 72. When the GUI 3300 is being programmed to a continuousvolume/time dose rate infusion, the VTBI parameter input field 3314 andthe time parameter input field 3316 are dependent on one another. A usermay only need to populate one of the VTBI parameter input field 3314 orthe time parameter input field 3316. The field left vacant by the usermay be calculated automatically and displayed on the GUI 3300.

FIG. 74 shows a scenario in which the infusion parameters beingprogrammed are those of a drug amount based infusion herein referred toas an intermittent infusion. In the example embodiment shown in FIG. 74,all of the parameter input fields have been populated. As shown, themedication parameter input field 3302 on the GUI 3300 has been populatedwith the antibiotic “VANCOMYCIN” as the defined infusate.

As shown, the in container drug amount parameter input field 3304, totalvolume in container input field 3306, and concentration parameter inputfield 3308 are laid out the same as in FIG. 73. In the exampleembodiment in FIG. 74, the left field of the in container drug amountparameter input field 3304 has been populated with “1”. The right fieldof the in container drug amount parameter input field 3304 has beenpopulated with “g”. Thus the total amount of Vancomycin in the containerhas been defined as one gram. The total volume in container parameterinput field 3306 has been populated with “250” ml. The left field of theconcentration parameter input field 3308 has been populated with “4.0”.The right field of the concentration parameter input field has beenpopulated with “mg/mL”.

As mentioned in relation to other possible types of infusions which auser may be capable of programming through the GUI 3300, the incontainer drug amount parameter input field 3304, total volume incontainer input field 3306, and concentration parameter input field 3308are dependent upon each other. As above, this is indicated by the curveddouble arrows connecting the parameter input field names. By populatingany two of these parameters, the third parameter may be automaticallycalculated and displayed on the correct parameter input field on the GUI3300.

In the example embodiment in FIG. 74, the dose parameter input field3310 has been populated. As shown, the dose parameter input field 3310comprises a right and left field. A numeric value may defined in theright field of the dose parameter input field 3310 by the user in thesame manner as a user may define values for other parameter input fieldswhich define numeric values. In the example embodiment in FIG. 74, theleft field of the dose parameter input field 3310 has been populatedwith the value “1000”.

The right field of the dose parameter input field 3310 may define a unitof mass measurement. To define the right field of the dose parameterinput field 3310, a user may touch the dose parameter input field 3310on the GUI 3300. In some embodiments, this may cull up a list ofacceptable possible units of measure. In such embodiments, the desiredunit of measure may be defined by a user in the same manner as a usermay define the correct infusate. In other embodiments, touching the doseparameter input field 3310 may cull up a virtual keyboard. The user maythen type the correct unit of measure on the virtual keyboard. In someembodiments the user may be required to tap, double tap, slide, etc. avirtual “confirm”, “enter”, etc. button to store the selection and moveon to a list of acceptable mass measurements. The desired massmeasurement may be defined by a user in the same manner as a user maydefine the correct infusate. In the example embodiment shown in FIG. 74the right field of the dose parameter input field 3310 is populated withthe unit of measurement “mg”.

As shown, the rate parameter input field 3312, VTBI parameter inputfield 3314, and the time parameter input field 3316 have been populated.As shown, the rate parameter input field 3312 has been populated with“125” mL/hr. The VTBI parameter input field 3314 has been defined as“250” mL. The time parameter input field 3316 has been defined as “2”hrs “00” min.

The user may not need to individually define each of the dose parameterinput field 3310, rate parameter input field 3312, VTBI parameter inputfield 3314, and the time parameter input field 3316. As indicated by thecurved double arrows, the dose parameter input field 3310 and the VTBIparameter input field 3314 are dependent upon each other. Input of onevalue may allow the other value to be automatically calculated anddisplayed by the GUI 3300. The rate parameter input field 3312 and thetime parameter input field 3316 are also dependent upon each other. Theuser may need to only define one value and then allow the non-definedvalue to be automatically calculated and displayed on the GUI 3300. Insome embodiments, the rate parameter input field 3312, VTBI parameterinput field 3314, and the time parameter input field 3316 may be lockedon the GUI 3300 until the in container drug amount parameter input field3304, total volume in container parameter input field 3306 andconcentration parameter input field 3308 have been defined. These fieldsmay be locked because automatic calculation of the rate parameter inputfield 3312, VTBI parameter input field 3314, and the time parameterinput field 3316 is dependent upon values in the in container drugamount parameter input field 3304, total volume in container parameterinput field 3306 and concentration parameter input field 3308.

In scenarios where an infusate may require a body weight based dosage, aweight parameter input field 3320 may also be displayed on the GUI 3300.The example GUI 3300 shown on FIG. 75 has been arranged such that a usermay program a body weight based dosage. The parameter input fields maybe defined by a user as detailed in the above discussion. In the exampleembodiment, the infusate in the medication parameter input field 3302has been defined as “DOPAMINE”. The left field of the in container drugamount parameter input field 3304 has been defined as “400”. The rightfield of the in container drug amount parameter input field 3304 hasbeen defined as “mg”. The total volume in container parameter inputfield 3306 has been defined as “250” ml. The left field of theconcentration parameter input field 3308 has been defined as “1.6”. Theright field of the concentration parameter input field 3308 has beendefined as “mg/mL”. The weight parameter input field 3320 has beendefined as “90” kg. The left field of the dose rater parameter inputfield 3318 has been defined as “5.0”. The right field of the dose rateparameter input field 3318 has been defined as “mcg/kg/min”. The rateparameter input field 3312 has been defined as “16.9” mL/hr. The VTBIparameter input field 3314 has been defined as “250” mL. The timeparameter input field 3316 has been defined as “14” hrs “48” min.

To define the weight parameter input field 3320, a user may touch or tapthe weight parameter input field 3320 on the GUI 3300. In someembodiments, this may cull up a number pad with a range of numbers, suchas 0-9 displayed as individual selectable virtual buttons. A user may berequired to input the parameter by individually tapping, double tapping,touching and dragging, etc. the desired numbers. Once the desired valuehas been input by a user, a user may be required to tap, double tap,etc. a virtual “confirm”, “enter”, etc. button to populate the field.

As indicated by the curved double arrows, some parameter input fieldsdisplayed on the GUI 3300 may be dependent upon each other. As inprevious examples, the in container drug amount parameter input field3304, total volume in container parameter input field 3306, andconcentration parameter input field 3308 may be dependent upon eachother. In FIG. 75, the weight parameter input field 3320, dose raterparameter input field 3318, rate parameter input field 3312, VTBIparameter input field 3314, and the time parameter input field 3316 areall dependent upon each other. When enough information has been definedby the user in these parameter input fields, the parameter input fieldsnot populated by the user may be automatically calculated and displayedon the GUI 3300.

In some embodiments, a user may be required to define a specificparameter input field even if enough information has been defined toautomatically calculate the field. This may improve safety of use bypresenting more opportunities for user input errors to be caught. If avalue entered by a user is not compatible with already defined values,the GUI 3300 may display an alert or alarm message soliciting the userto double check values that the user has entered.

In some scenarios the delivery of infusate may be informed by the bodysurface area (BSA) of a patient. In FIG. 76, the GUI 3300 has been setup for a body surface area based infusion. As shown, a BSA parameterinput field 3322 may be displayed on the GUI 3300. The parameter inputfields may be defined by a user as detailed in the above discussion. Inthe example embodiment, the infusate in the medication parameter inputfield 3302 has been defined as “FLUOROURACIL”. The left field of the incontainer drug amount parameter input field 3304 has been defined as“1700”. The right field of the in container drug amount parameter inputfield 3304 has been defined as “mg”. The total volume in containerparameter input field 3306 has been defined as “500” ml. The left fieldof the concentration parameter input field 3308 has been defined as“3.4”. The right field of the concentration parameter input field 3308has been defined as “mg/mL”. The BSA parameter input field 3320 has beendefined as “1.7” m². The left field of the dose rate parameter inputfield 3318 has been defined as “1000”. The right field of the dose rateparameter input field 3318 has been defined as “mg/m2/day”. The rateparameter input field 3312 has been defined as “20.8” mL/hr. The VTBIparameter input field 3314 has been defined as “500” mL. The timeparameter input field 3316 has been defined as “24” hrs “00” min. Thedependent parameter input fields are the same as in FIG. 75 with theexception that the BSA parameter input field 3322 has taken the place ofthe weight parameter input field 3320.

To populate the BSA parameter input field 3322, the user may touch ortap the BSA parameter input field 3322 on the GUI 3300. In someembodiments, this may cull up a number pad with a range of numbers, suchas 0-9 displayed as individual selectable virtual buttons. In someembodiments, the number pad and any of the number pads detailed abovemay also feature symbols such as a decimal point. A user may be requiredto input the parameter by individually tapping, double tapping, touchingand dragging, etc. the desired numbers. Once the desired value has beeninput by a user, a user may be required to tap, double tap, etc. avirtual “confirm”, “enter”, etc. button to populate the field.

In some embodiments, a patient's BSA may be automatically calculated anddisplayed on the GUI 3300. In such embodiments, the GUI 3300 may querythe user for information about the patient when a user touches, taps,etc. the BSA parameter input field 3322. For example, the user may beasked to define a patient's height and body weight. After the userdefines these values they may be run through a suitable formula to findthe patient's BSA. The calculated BSA may then be used to populate theBSA parameter input field 3322 on the GUI 3300.

In operation, the values displayed in the parameter input fields maychange throughout the course of a programmed infusion to reflect thecurrent state of the infusion. For example, as the infusate is infusedto a patient, the values displayed by the GUI 3300 in the in containerdrug amount parameter input field 3304 and total volume in containerparameter input field 3306 may decline to reflect the volume of theremaining contents of the container. Additionally, the values in theVTBI parameter input field 3314 and time parameter input field 3316 mayalso decline as infusate is infused to the patient.

FIG. 77 is an example rate over time graph detailing one behavioralconfiguration of a syringe pump 500 (see FIG. 28) over the course of aninfusion. Though the following discussion mostly details behavioralconfigurations of a syringe pump 500, it should be appreciated that thegraphs shown in FIG. 77-81 may also detail the behavioral configurationsof other pumps, including the other pumps mentioned in thisspecification. The graph in FIG. 77 details an example behavioralconfiguration of the syringe pump 500 where the infusion is a continuousinfusion (an infusion with a dose rate). As shown, the graph in FIG. 77begins at the initiation of infusion. As shown, the infusion isadministered at a constant rate for a period of time. As the infusionprogresses, the amount of infusate remaining is depleted.

When the amount of infusate remaining reaches a pre-determinedthreshold, an “INFUSION NEAR END ALERT” may be triggered. The point atwhich “INFUSION NEAR END ALERT” is issued may be configured by the user.The “INFUSION NEAR END ALERT” may also be configured to be triggeredsooner on short-half life drugs. The “INFUSION NEAR END ALERT” may be inthe form of a message on the GUI 3300 and may be accompanied by flashinglights, and audible noises such as a series of beeps. The “INFUSION NEAREND ALERT” allows time for the care giver and pharmacy to preparematerials to continue the infusion if necessary. As shown, the infusionrate may not change over the “INFUSION NEAR END ALERT TIME”.

When the syringe pump 500 (see FIG. 28) has infused the VTBI to apatient a “VTBI ZERO ALERT” may be triggered. The “VTBI ZERO ALERT” maybe in the form of a message on the GUI 3300 and may be accompanied byflashing lights and audible noises such as beeps. As shown, the “VTBIZERO ALERT” causes the pump to switch to a keep-vein-open (hereafterKVO) rate until a new infusate container may be put in place. The KVOrate is a low infusion rate (for example 5-25 mL/hr). The rate is set tokeep the infusion site patent until a new infusion may be started. TheKVO rate may be configurable by the group (elaborated upon later) ormedication and can be modified on the syringe pump 500. The KVO rate isnot allowed to exceed the continuous infusion rate. When the KVO ratecan no longer be sustained and the syringe has reached the end of itsstoke, an “END OF STROKE ALARM” may be triggered. When the “END OFSTROKE ALARM” is triggered, all infusion may stop. The “END OF STROKEALARM” may be in the form of a message on the GUI 3300 and may beaccompanied by flashing lights and audible noises such as beeps.

FIG. 78 shows another example rate over time graph detailing onebehavioral configuration of a syringe pump 500 (see FIG. 28) over thecourse of an infusion. The graph in FIG. 78 details an examplebehavioral configuration of a syringe pump 500 where the infusion is acontinuous infusion (an infusion with a dose rate). The alerts in thegraph shown in FIG. 78 are the same as the alerts shown in the graph inFIG. 77. The conditions which propagate the alerts are also the same.The rate, however, remains constant throughout the entire graph untilthe “END OF STROKE ALERT” is triggered and the infusion is stopped. Bycontinuing infusion at a constant rate, it is ensured that the bloodplasma concentration of the drug remains at therapeutically effectivelevels. Configuring the pump to continue infusion at a constant rate maybe especially desirable in situations where the infusate is a drug witha short half-life. In some embodiments, the end of infusion behavior ofthe syringe pump 500 may be restricted depending on the definedinfusate. For example, when the defined infusate is a short half-lifedrug the end of infusion behavior of the syringe pump 500 may be limitedonly to continuing to infuse at the rate of the finished infusion.

The syringe pump 500 (see FIG. 28) may also be used to deliver a primaryor secondary intermittent infusion. During an intermittent infusion, anamount of a drug (dose) is administered to a patient as opposed to acontinuous infusion where the drug is given at a specified dose rate(amount/time). An intermittent infusion is also delivered over a definedperiod of time, however, the time period and dose are independent of oneanother. The previously described FIG. 73 shows a setup of the GUI 3300for a continuous infusion. The previously described FIG. 74 shows asetup of the GUI 3300 for an intermittent infusion.

FIG. 79 is an example rate over time graph detailing the one behavioralconfiguration of a syringe pump 500 (see FIG. 28) over the course of anintermittent infusion. As shown, the intermittent infusion is given at aconstant rate until all infusate programmed for the intermittentinfusion has been depleted. In the example behavioral configuration, thesyringe pump 500 has been programmed to issue a “VTBI ZERO ALERT” andstop the infusion when all the infusate has been dispensed. In thisconfiguration, the user may be required to manually clear the alertbefore another infusion may be started or resumed.

Depending on the group (further elaborated upon later) or themedication, it may be desirable to configure the syringe pump 500 tobehave differently at the end of an intermittent infusion. Otherconfigurations may cause a syringe pump 500 (see FIG. 28) to behavedifferently. For example, in scenarios where the intermittent infusionis a secondary infusion, the pump 201, 202, 203 (see FIG. 2) may beconfigured to automatically switch back to the primary infusion afterissuing a notification that the secondary intermittent infusion has beencompleted. In alternate configurations, the a syringe pump 500 may beconfigured issue a “VTBI ZERO ALERT” and drop the infusion rate to a KVOrate after completing the intermittent infusion. In such configurations,the user may be required to manually clear the alert before a primaryinfusion is resumed.

A bolus may also be delivered as a primary intermittent infusion when itmay be necessary or desirable to achieve a higher blood plasma drugconcentration or manifest a more immediate therapeutic effect. In suchcases, the bolus may be delivered by a pump 201, 202, 203 (see FIG. 2)executing the primary infusion. The bolus may be delivered from the samecontainer which the primary infusion is being delivered from. A bolusmay be performed at any point during an infusion providing there isenough infusate to deliver the bolus. Any volume delivered via a bolusto a patient is included in the value displayed by the VTBI parameterinput field 3314 of the primary infusion.

Depending on the infusate, a user may be forbidden from performing abolus. The dosage of a bolus may be pre-set depending on the specificinfusate or infusate concentration being used. Additionally, the periodof time over which the bolus occurs may be pre-defined depending on theinfusate being used. After performing a bolus, the bolus function may belocked for a pre-defined period of time. In some embodiments, a user maybe capable of adjusting these pre-sets by adjusting various setting onthe GUI 3300. In some situations, such as those where the drug beinginfused has a long half-life (vancomycin, teicoplanin, etc.), a bolusmay be given as a loading dose to more quickly reach a therapeuticallyeffective blood plasma drug concentration.

FIG. 80 shows another rate over time graph in which the flow rate of theinfusate has been titrated to “ramp” the patient up on the infusate.Titration is often used with drugs which register a fast therapeuticeffect, but have a short half life (such as norepinephrine). Whentitrating, the user may adjust the delivery rate of the infusate untilthe desired therapeutic effect is manifested. Every adjustment may bechecked against a series of limits defined for the specific infusatebeing administered to the patient. If an infusion is changed by morethan a pre-defined percentage, an alert may be issued. In the exemplarygraph shown in FIG. 80, the rate has been up-titrated once. Ifnecessary, the rate may be up-titrated more than one time. Additionally,in cases where titration is being used to “wean” a patient off of adrug, the rate may be down-titrated any suitable number of times.

FIG. 81 is another rate over time graph in which the infusion has beenconfigured as a multi-step infusion. A multi-step infusion may beprogrammed in a number of different steps. Each step may be defined by aVTBI, time, and a dose rate. Multi-step infusions may be useful forcertain types of infusates such as those used for parenteral nutritionapplications. In the example graph shown in FIG. 81, the infusion hasbeen configured as a five step infusion. The first step infuses a “VTBI1” for a length of time, “Time 1”, at a constant rate, “Rate 1”. Whenthe time interval for the first step has elapsed, the pump moves on tothe second step of the multi-step infusion. The second step infuses a“VTBI 2” for a length of time, “Time 2”, at a constant rate, “Rate 2”.As shown, “Rate 2” is higher than “Rate 1”. When the time interval forthe second step has elapsed, the pump moves on to the third step of themulti-step infusion. The third step infuses a “VTBI 3” for a length oftime, “Time 3”, at a constant rate, “Rate 3”. As shown “Rate 3” is thehighest rate of any steps in the multi-step infusion. “Time 3” is alsothe longest duration of any step of the multi-step infusion. When thetime interval for the third step has elapsed, the pump move on to thefourth step of the multi-step infusion. The fourth step infuses a “VTBI4” for a length of time, “Time 4”, at a constant rate, “Rate 4”. Asshown, “Rate 4” has been down-titrated from “Rate 3”. “Rate 4” isapproximately the same as “Rate 2”. When the time interval for thefourth step of the multi-step infusion has elapsed, the pump move on tothe fifth step. The fifth step infuses a “VTBI 5” for a length of time,“Time 5”, at a constant rate, “Rate 5”. As shown, “Rate 5” has beendown-titrated from “Rate 4” and is approximately the same as “Rate 1”.

The “INFUSION NEAR END ALERT” is triggered during the fourth step of theexample infusion shown in FIG. 81. At the end of the fifth and finalstep of the multi-step infusion, the “VTBI ZERO ALERT” is triggered. Inthe example configuration shown in the graph in FIG. 81, the rate isdropped to a KVO rate after the multi-step infusion has been concludedand the “VTBI ZERO ALERT” has been issued. Other configurations maydiffer.

Each rate change in a multi-step infusion may be handled in a variety ofdifferent ways. In some configurations, the syringe pump 500 (see FIG.2) may display a notification and automatically adjust the rate to moveon to the next step. In other configurations, the syringe pump 500 mayissue an alert before changing the rate and wait for confirmation fromthe user before adjusting the rate and moving on to the next step. Insuch configurations, the pump 500 may stop the infusion or drop to a KVOrate until user confirmation has been received.

In some embodiments, the user may be capable of pre-programminginfusions. The user may pre-program an infusion to automatically beingafter a fixed interval of time has elapsed (e.g. 2 hours). The infusionmay also be programmed to automatically being at a specific time of day(e.g. 12:30 pm). In some embodiments, the user may be capable ofprogramming the syringe pump 500 (see FIG. 28) to alert the user with acallback function when it is time to being the pre-programmed infusion.The user may need to confirm the start of the pre-programmed infusion.The callback function may be a series of audible beeps, flashing lights,or the like.

In arrangements where there is more than one pump 201, 202, 203 (seeFIG. 2), the user may be able to program a relay infusion. The relayinfusion may be programmed such that after a first pump 201, 202, 203has completed its infusion, a second pump 201, 202, 203 mayautomatically being a second infusion and so on. The user may alsoprogram a relay infusion such that the user is alerted via the callbackfunction before the relay occurs. In such a programmed arrangement, therelay infusion may not being until confirmation from a user has beenreceived. A pump 201, 202, 203 may continue at a KVO rate until userconfirmation has been received.

FIG. 82 shows an example block diagram of a “Drug AdministrationLibrary” data structure. The data structure may be stored in any fileformat or in any database (e.g., an SQL database). In the upper righthand corner there is a box which is substantially rectangular, thoughits edges are rounded. The box is associated with the name “GeneralSettings”. The “General Settings” may include settings which would becommon to all devices in a facility such as, site name (e.g. XZYHospital), language, common passwords, and the like.

In FIG. 82, the “Drug Administration Library” has two boxes which areassociated with the names “Group Settings (ICU)” and “Group Settings”.These boxes form the headings for their own columns. These boxes may beused to define a group in within a facility (e.g. pediatric intensivecare unit, emergency room, sub-acute care, etc.) in which the device isstationed. Groups may also be areas outside a parent facility, forexample, a patient's home or an inter-hospital transport such as anambulance. Each group may be used to set specific settings for variousgroups within a facility (weight, titration limits, etc.). These groupsmay alternatively be defined in other manners. For example, the groupsmay be defined by user training level. The group may be defined by aprior designated individual or any of a number of prior designatedindividuals and changed if the associated patient or device is movedfrom one specific group within a facility to another.

In the example embodiment, the left column is “Group Settings (ICU)”which indicates that the syringe pump 500 (see FIG. 28) is stationed inthe intensive care unit of the facility. The right column is “GroupSettings” and has not been further defined. In some embodiments, thiscolumn may be used to designate a sub group, for example operatortraining level. As indicated by lines extending to the box off to theleft of the block diagram from the “Group settings (ICU)” and “GroupSettings” columns, the settings for these groups may include a presetnumber of default settings.

The group settings may include limits on patient weight, limits onpatient BSA, air alarm sensitivity, occlusion sensitivity, default KVOrates, VTBI limits, etc. The group settings may also include parameterssuch as whether or not a review of a programmed infusion is necessaryfor high risk infusates, whether the user must identify themselvesbefore initiating an infusion, whether the user must enter a textcomment after a limit has been overridden, etc. A user may also definethe defaults for various attributes like screen brightness, or speakervolume. In some embodiments, a user may be capable of programming thescreen to automatically adjust screen brightness in relation to one ormore conditions such as but not limited to time of day.

As also shown to the left of the block diagram in FIG. 82, each facilitymay have a “Master Medication List” defining all of the infusates whichmay be used in the facility. The “Master Medication List” may comprise anumber of medications which a qualified individual may update ormaintain. In the example embodiment, the “Master Medication List” onlyhas three medications: Heparin, 0.9% Normal Saline, and Alteplase. Eachgroup within a facility may have its own list of medications used in thegroup. In the example embodiment, the “Group Medication List (ICU)” onlyincludes a single medication, Heparin.

As shown, each medication may be associated with one or a number ofclinical uses. In FIG. 82 the “Clinical Use Records” are defined foreach medication in a group medication list and appear as an expandedsub-heading for each infusate. The clinical uses may be used to tailorlimits and pre-defined settings for each clinical use of the infusate.For Heparin, weight based dosing and non-weight based dosing are shownin FIG. 82 as possible clinical uses. In some embodiments, there may bea “Clinical Use Record” setting requiring the user to review or re-entera patient's weight (or BSA) before beginning an infusion.

Clinical uses may also be defined for the different medical uses of eachinfusate (e.g. stroke, heart attack, etc.) instead of or in addition tothe infusate's dose mode. The clinical use may also be used to definewhether the infusate is given as a primary continuous infusion, primaryintermittent infusion, secondary infusion, etc. They may also be use toprovide appropriate limits on the dose, rate, VTBI, time duration, etc.Clinical uses may also provide titration change limits, the availabilityof boluses, the availability of loading doses, and many other infusionspecific parameters. In some embodiments, it may be necessary to provideat least one clinical use for each infusate in the group medicationlist.

Each clinical use may additionally comprise another expanded sub-headingin which the concentration may also be defined. In some cases, there maybe more than one possible concentration of an infusate. In the exampleembodiment in FIG. 82, the weight base dosing clinical use has a 400mg/250 mL concentration and an 800 mg/250 mL concentration. Thenon-weight based dosing clinical use only has one concentration, 400mg/mL. The concentrations may also be used to define an acceptable rangefor instances where the user may customize the concentration of theinfusate. The concentration setting may include information on the drugconcentration (as shown), the diluents volume, or other relatedinformation.

In some embodiments, the user may navigate to the “Drug AdministrationLibrary” to populate some of the parameter input fields shown in FIGS.72-76. The user may also navigate to the “Drug Administration Library”to choose from the clinical uses for each infusate what type of infusionthe syringe pump 500 (see FIG. 28) will administer. For example, if auser were to select weight based Heparin dosing on FIG. 82, the GUI 3300might display the infusion programming screen shown on FIG. 75 with“Heparin” populated into the medication parameter input field 3302.Selecting a clinical use of a drug may also prompt a user to select adrug concentration. This concentration may then be used to populate theconcentration parameter input field 3308 (see FIGS. 72-76). In someembodiments, the “Drug Administration Library” may be updated andmaintained external to the syringe pump 500 and communicated to thesyringe pump 500 via any suitable means. In such embodiments, the “DrugAdministration Library” may not be changeable on the syringe pump 500but may only place limits and/or constraints on programming options fora user populating the parameter input fields shown in FIG. 72-76.

As mentioned above, by choosing a medication and clinical use from thegroup medication list, a user may also be setting limits on otherparameter input fields for infusion programming screens. For example, bydefining a medication in the “Drug Administration Library” a user mayalso be defining limits for the dose parameter input field 3310, doserate parameter input field 3318, rate parameter input field 3312, VTBIparameter input field 3314, time parameter input field 3316, etc. Theselimits may be pre-defined for each clinical use of an infusate prior tothe programming of an infusion by a user. In some embodiments, limitsmay have both a soft limit and a hard limit with the hard limit beingthe ceiling for the soft limit. In some embodiments, the group settingsmay include limits for all of the medications available to the group. Insuch cases, clinical use limits may be defined to further tailor thegroup limits for each clinical usage of a particular medication.

The software architecture of the syringe pump 500 is shown schematicallyin FIG. 83. The software architecture divides the software intocooperating subsystems that interact to carry out the required pumpingaction. The software is equally applicable to all the embodimentsdescribed herein. It is also possible to apply the software to otherpumps not described herein. Each subsystem may be composed of one ormore execution streams controlled by the underlying operating system.Useful terms used in the art include operating system, subsystem,process, thread and task.

Asynchronous messages 4130 are used to ‘push’ information to thedestination task or process. The sender process or task does not getconfirmation of message delivery. Data delivered in this manner istypically repetitive in nature. If messages are expected on a consistentschedule, the receiver process or task can detect a failure if a messagedoes not arrive on time.

Synchronous messages 4120 may be used to send a command to a task orprocess, or to request (‘pull’) information from a process or task.After sending the command (or request), the originating task or processsuspends execution while awaiting a response. The response may containthe requested information, or may acknowledge the receipt of the sentmessage. If a response is not received in a timely manner, the sendingprocess or task may time out. In such an event, the sending process ortask may resume execution and/or may signal a error condition.

An operating system (OS) is a collection of software that managescomputer hardware resources and provides common services for computerprograms. The operating system may act as an intermediary betweenprograms and the computer hardware. Although some application code maybe executed directly by the hardware, the application code mayfrequently make a system call to an OS function or be interrupted by it.

The RTP 3500 may run on a Real Time Operating System (RTOS) that hasbeen certified to a safety level for medical devices. An RTOS is amultitasking operating system that aims at executing real-timeapplications. Real-time operating systems often use specializedscheduling algorithms so that they can achieve a deterministic nature ofbehavior. The UIP 3600 may run on a Linux operating system. The Linuxoperating system is a Unix-like computer operating system.

A subsystem is a collection of software (and perhaps hardware) assigneda specific set of (related) system functionality or functionalities. Asubsystem has clearly defined responsibilities and a clearly definedinterface to other subsystems. A subsystem is an architectural divisionof the software that uses one or more processes, threads or tasks.

A process is an independent executable running on a Linux operatingsystem which runs in its own virtual address space. The memorymanagement hardware on the CPU is used to enforce the integrity andisolation of this memory, by write protecting code-space, anddisallowing data access outside of the process' memory region. Processescan only pass data to other processes using inter-process communicationfacilities.

In Linux, a thread is a separately scheduled, concurrent path of programexecution. On Linux, a thread is always associated with a process (whichmust have at least one thread and can have multiple threads). Threadsshare the same memory space as its ‘parent’ process. Data can bedirectly shared among all of the threads belonging to a process but caremust be taken to properly synchronize access to shared items. Eachthread has an assigned execution priority.

A Task on an RTOS (Real Time Operating System) is a separatelyscheduled, concurrent path of program execution, analogous to a Linux‘thread’. All tasks share the same memory address space which consistsof the entire CPU memory map. When using an RTOS that provides memoryprotection, each task's effective memory map is restricted by the MemoryProtection Unit (MPU) hardware to the common code space and the task'sprivate data and stack space.

The processes on the UIP 3600, communicate via IPC calls as shown by theone-way arrows in FIG. 83. Each solid-lined arrow represents asynchronous message 4120 call and response, and dotted-line arrows areasynchronous messages 4130. The tasks on the RTP 3500 similarlycommunicate with each other. The RTP 3500 and UIP 3600 may be bridged byan asynchronous serial line 3601, with one of an InterComm Process 4110or InterComm Task 4210 on each side. The InterComm Process 4110 presentsthe same communications API (Application Programming Interface) on bothsides of the bridge, so all processes and tasks can use the same methodcalls to interact.

The Executive Process 4320 may invoked by the Linux system startupscripts after all of the operating system services have started. TheExecutive Process 4320 then starts the various executable files thatcomprise the software on the UIP 3600. If any of the software componentsshould exit or fail unexpectedly, the Executive Process 4320 may benotified, and may generate the appropriate alarm.

While the system is running, the Executive Process 4320 may act as asoftware ‘watchdog’ for various system components. After registeringwith the Executive Process 4320, a process is required to ‘check in’ orsend a signal periodically to the Executive Process 4320. Failure to‘check in’ at the required interval may be detected by the ExecutiveProcess 4320. Upon detection of a failed subsystem, the ExecutiveProcess 4320 may take remedial action of either: do nothing, declaringan alarm, or restarting the failed process. The remedial action taken ispredetermined by a table entry compiled into the Executive Process 4320.The ‘check-in’ interval may vary from process to process. The amount ofvariance between ‘check-in’ times for different processes may be basedin part on the importance of the process. The check-in interval may alsovary during syringe pump 500 operation to optimize the pump controllerresponse by minimizing computer processes. In one example embodiment,during syringe 504 loading, the pump controller may check-in lessfrequently than during active pumping.

In response to the required check-in message, the Executive Process 4320may return various system status items to processes that checked-in. Thesystem status items may be the status of one or more components on thesyringe pump 500 and/or errors. The System Status items may include:battery status, WiFi connection status, device gateway connectionstatus, device status (Idle, Infusion Running, Diagnostic Mode, Error,Etc.), technical error indications, and engineering log levels.

A thread running in the Executive Process 4320 may be used to read thestate of the battery 3420 from an internal monitor chip in the battery3420. This may be done at a relatively infrequent interval such as every10 seconds.

The UI View 4330 implements the graphical user interface (GUI 3300 seeFIG. 71), rendering the display graphics on the display 514, andresponding to inputs on the touch screen in embodiments comprising atouch screen or to inputs communicated via other data input means 516.The UI View 4330 design is stateless. The graphic being displayed may becommanded by the UI Model Process 4340, along with any variable data tobe displayed. The commanded graphic may be refreshed periodicallyregardless of data changes.

The style and appearance of user input dialogs (Virtual keyboard, dropdown selection list, check box etc.) may be specified by the screendesign, and implemented entirely by the UI View 4330. User input may becollected by the UI View 4330, and sent to the UI Model 4340 forinterpretation. The UI View 4330 may provide for multi-region,multi-lingual support with facilities for the following list includingbut not limited to: virtual keyboards, unicode strings, loadable fonts,right to left entry, translation facility (loadable translation files),and configurable numbers and date formats.

The UI Model 4340 implements the screen flows, and so controls the userexperience. The US Model 4340 interacts with the UI View 4330,specifying the screen to display, and supplies any transient values tobe displayed on the screen. Here screen refers the image displayed onthe physical display 514 and the defined interactive areas or userdialogs i.e. buttons, sliders, keypads etc, on the touch screen 3735.The UI Model 4340 interprets any user inputs sent from the UI View 4330,and may either update the values on the current screen, command a newscreen, or pass the request to the appropriate system service (i.e.‘start pumping’ is passed to the RTP 3500).

When selecting a medication to infuse from the Drug AdministrationLibrary, the UI Model 4340 interacts with the Drug AdministrationLibrary stored in the local data base which is part of the DatabaseSystem 4350. The user's selections setup the run time configurations forprogramming and administering the desired medication.

While the operator is entering an infusion program, The UI Model 4340may relay the user's input values to the Infusion Manager 4360 forvalidation and interpretation. Therapeutic decisions may not be made bythe UI Model 4340. The treatment values may be passed from the InfusionManager 4360 to the UI Model 4340 to the UI View 4330 to be displayedfor the user.

The UI Model 4340 may continuously monitor the device status gatheredfrom the Infusion Manager 4360 (current infusion progress, alerts, etc.)for possible display by the UI View 4330. Alerts/Alarms and otherchanges in system state may provoke a screen change by the UI Model4340.

The Infusion Manager Process (IM) 4360 may validate and controls theinfusion delivered by the syringe pump 500. To start an infusion, theuser may interact with the UI View/Model 4330/4340 to select a specificmedication and clinical use. This specification selects one specificDrug Administration Library (DAL) entry for use. The IM 4360 loads thisDAL entry from the database 4350, for use in validating and running theinfusion.

Once a Drug Administration Library entry is selected, the IM 4340 maypass the dose mode, limits for all user enterable parameters, and thedefault values (if set) up to the UI Model 4340. Using this data, the UIModel 4340 may guide the user in entering the infusion program.

As each parameter is entered by the user, the value may sent from the UIView/Model 4330/4340 to the IM 4360 for verification. The IM 4360 echoesthe parameters back to the UI View/Model 4330/4340, along with anindication of the parameter's conformance to the DAL limits. This allowsthe UI View/Model 4330/4340 to notify the user of any values that areout of bounds.

When a complete set of valid parameters has been entered, the IM 4360also may return a valid infusion indicator, allowing the UI View/Model4330/4340 to present a ‘Start’ control to the user.

The IM 4360 may simultaneously make the infusion/pump status availableto the UI View/Model 4330/4340 upon request. If the UI View/Model4330/4340 is displaying a ‘status’ screen, it may request this data topopulate it. The data may be a composite of the infusion state, and thepump state.

When requested to run the (valid) infusion, the IM 4360 may pass the‘Infusion Worksheet’ containing user specified data and the ‘InfusionTemplate’ containing the read-only limits from the DAL as a CRC′d binaryblock to the Infusion Control Task 4220 running on the RTP 3500. TheInfusion Control Task 4220 on the RTP 3500 takes the same user inputs,conversions and DERS inputs and recalculates the Infusion Worksheet. TheInfusion Control Task 4220 calculated results may be stored in a secondCRC′d binary block and compared to the first binary block from the UIP3600. The infusion calculations performed on the UIP 3600 may berecalculated and double checked on the RTP 3500 before the infusion isrun.

Coefficients to convert the input values (ie. □l, grams, %, etc.) to astandard unit such as ml may be stored in the UIP 3600 memory ordatabase system 4350. The coefficients may be stored in a lookup tableor at specific memory locations. The lookup table may contain 10's ofconversion values. In order to reduce the chance that flipping a singlebit will resulting in the wrong conversion factor being used, theaddresses for the conversion values may be distributed among the valuesfrom zero to 4294967296 or 2³². The addresses may be selected so thatthe binary form of one address is never just one bit different from asecond address.

While an infusion is running, the IM 4360 may monitor its progress,sequences, pauses, restarts, secondary infusions, boluses, and KVO (keepvein open) scenarios as needed. Any user alerts requested during theinfusion (Infusion near complete, KVO callback, Secondary completecallback, etc) may be tracked and triggered by the IM 4360.

Processes on the UIP 3600 may communicate with each other via aproprietary messaging scheme based on a message queue library that isavailable with Linux. The system provides for both acknowledged(synchronous message 4120) and unacknowledged (asynchronous message4130) message passing.

Messages destined for the Real-time Processor (RTP) 3500 may be passedto the InterComm Process 4310 which forwards the messages to the RTP3500 over a serial link 3601. A similar InterComm Task 4210 on the RTP3500 may relay the message to its intended destination via the RTP 3500messaging system.

The messaging scheme used on this serial link 3601 may provide for errordetection and retransmission of flawed messages. This may be needed toallow the system to be less susceptible to electrical disturbances thatmay occasionally ‘garble’ inter-processor communications.

To maintain a consistent interface across all tasks, the messagepayloads used with the messaging system may be data classes derived froma common baseclass (MessageBase). This class adds both data identity(message type) and data integrity (CRC) to messages.

The Audio Server Process 4370 may be used to render sounds on thesystem. All user feedback sounds (key press beeps) and alarm or alerttones may be produced by playing pre-recorded sound files. The soundsystem may also be used to play music or speech if desired.

Sound requests may be symbolic (such as “Play High Priority AlarmSound”), with the actual sound file selection built into the AudioServer process 4370. The ability to switch to an alternative soundscapemay be provided. This ability may be used to customize the sounds forregional or linguistic differences.

The Device Gateway Communication Manager Process (DGCM) 4380 may managecommunications with the Device Gateway Server over a Wi-Fi network 3620,3622,3720. The DGCM 4380 may be started and monitored by the ExecutiveProcess 4320. If the DGCM 4380 exits unexpectedly, it may be restartedby the Executive Process 4320 but if the failures are persistent thesystem may continue to function without the gateway running.

It may be the function of the DGCM 4380 to establish and maintain theWi-Fi connection and to then establish a connection to the DeviceGateway. All interactions between the DGCM 4380 and the Device Gatewayuse a system such as the system described in the cross referencednonprovisional application for System, Method, and Apparatus forElectronic Patient Care (Attorney Docket No. J85).

If the connection to the gateway is unavailable or becomes unavailable,the DGCM 4380 may discontinue any transfers in progress, and attempt toreconnect the link. Transfers may be resumed when the link isreestablished. Network and Gateway operational states are reportedperiodically to the Executive Process 4320. The Executive Process 4320distributes this information for display to the user.

The DGCM 4380 may function as an autonomous subsystem, polling theDevice Gateway Server for updates, and downloading newer items whenavailable. In addition the DGCM 4380 may monitor the logging tables inthe database, uploading new log events as soon as they are available.Events that are successfully uploaded may be flagged as such in thedatabase. After a reconnection to the Device Gateway Server, the DGCM4380 may ‘catch up’ with the log uploads, sending all items that wereentered during the communications disruption. Firmware and DrugAdministration Library updates received from the Gateway may be stagedin the UIP's 3600 file system for subsequent installation. Infusionprograms, clinical advisories, patient identification and other dataitems destined for the device may be staged in the database.

The DGCM 4380 may report connection status and date/time updates to theExecutive Process 4320. There may not be other direct connectionsbetween the DGCM 4380 and any of the other operational software. Such adesign decouples the operational software from the potentially transientavailability of the Device Gateway and Wi-Fi network.

The Motor Check 4383 software may read a hardware counter or encoder1202 (FIG. 60) that reports motor 1200 rotation. The software in thismodule may independently estimate the motor's 1200 movements, andcompare them to the expected motion based on the user inputs for rate ofinfusion. This may be an independent check for proper motor control.However, the primary motor 1200 control software may executed on the RTP3500.

Event information may be written to a log via the Logging Process 4386during normal operation. These events may consist of internal machinestatus and measurements, as well as therapy history events. Due to thevolume and frequency of event log data, these logging operations may bebuffered in a FIFO queue while waiting to be written to the database.

A SQL database (PostgreSQL) may be used to store the Drug AdministrationLibrary, Local Machine Settings, Infusion History and Machine Log data.Stored procedures executed by the database server may be used toinsulate the application from the internal database structures.

The database system 4350 may be used as a buffer for log data destinedfor the Device Gateway server, as well as a staging area for infusionsettings and warnings sent to the pump from the Gateway.

Upon requesting the start of an infusion, the DAL entry and all userselected parameters may be sent to the Infusion Control Task 4220. Allof the DAL validations and a recalculation of the infusion rate andvolume based upon the requested dose may be performed. The result may bechecked against the results calculated by the IM 4360 on the UIP 3600.These results may be required to match to continue.

When running an infusion, the Infusion Control Task 4220 may control thedelivery of each infusion ‘segment’; i.e. one part of an infusionconsisting of a volume and a rate. Examples of segments are: a primaryinfusion, KVO, bolus, remainder of primary after bolus, primary aftertitration, etc. The infusion segments are sequenced by the IM Process4360 on the UIP 3600.

The Pump Control Task 4250 may incorporate the controllers that drivethe pumping mechanism. The desired pumping rate and amount (VTBI) may bespecified in commands sent from the Infusion Control Task 4220.

The Pump Control 4250 may receive periodic sensor readings from theSensor Task 4264. The new sensor readings may be used to determine themotor speed and position, and to calculate the desired command to sendto the Brushless Motor Control IRQ 4262. The receipt of the sensormessage may trigger a recalculation of the controller output.

While pumping fluid, the Pump Control Task 4250 may perform at least oneof the following tasks: controlling pumping speed, measuring volumedelivered, measuring air detected (over a rolling time window),measuring fluid pressure or other indications of occlusions, anddetecting upstream occlusions.

Relevant measurements may be reported to the RTP Status Task 4230periodically. The Pump Control 4250 may execute one infusion segment ata time, stopping when the commanded delivery volume has been reached.The Sensor Task 4264 may read and aggregate the sensor data used for thedynamic control of the pumping system.

The sensor task 4264 may be scheduled to run at a consistent 1 kHz rate(every 1.0 ms) via a dedicated counter/timer. After all of the relevantsensors are read, the data may be passed to the Pump Control Task 4250via an asynchronous message 4120. The periodic receipt of this messagemay be used as the master time base to synchronize the syringe pump's500 control loops.

The RTP Status Task 4230 may be the central repository for both thestate and the status of the various tasks running on the RTP 3500. TheRTP Status Task 4230 may distribute this information to both the IM 4360running on the UIP 3600, as well as to tasks on the RTP 3500 itself.

The RTP Status Task 4230 may also be charged with fluid accounting forthe ongoing infusion. Pump starts and stops, as well as pumping progressmay be reported to RTP Status 4230 by the Pump Control Task 4256. TheRTP Status Task 4230 may account for at least one of the following:total volume infused, primary volume delivered, primary VTBI (counteddown), volume delivered and VTBI of a bolus while the bolus is inprogress, and volume delivered and VTBI of a secondary infusion whilethe secondary infusion is in progress.

All alerts or alarms originating on the RTP 3500 may be funneled throughthe RTP Status Task 4230, and subsequently passed up to the UIP 3600.

While the unit is in operation, the program flash, and RAM memory may becontinually tested by the Memory Checker Task 4240. This test may benon-destructive. This test may be scheduled so that the entire memoryspace on the RTP 3500 is tested every few hours. Additional periodicchecks may be scheduled under this task if needed.

Tasks running on the RTP 3500 may be required to communicate with eachother as well as to tasks that are executing on the UIP 3600.

The RTP 3500 messaging system may use a unified global addressing schemeto allow messages to be passed to any task in the system. Local messagesmay be passed in memory utilizing the facilities of the RTOS' messagepassing, with off-chip messages routed over the asynchronous serial link3601 by the InterComm Task 4210.

The InterComm Task 4210 may manage the RTP 3500 side of the serial link3601 between the two processors. The InterComm Task 4210 is the RTP 3500equivalent of the InterComm Process 4310 on the UIP 3600. Messagesreceived from the UIP 3600 may be relayed to their destination on theRTP 3500. Outbound messages may be forwarded to InterComm Process 4310on the UIP 3600.

All messages between the RTP 3500 and the UIP 3600 may be checked fordata corruption using an error-detecting code (32 bit CRC). Messagessent over the serial link 3601 may be re-sent if corruption is detected.This provides a communications system that is reasonably tolerant toESD. Corrupted messages within the processor between processes may behandled as a hard system failure. All of the message payloads used withthe messaging system may be data classes derived from a common baseclass(MessageBase) to assure consistency across all possible messagedestinations.

Brushless Motor Control IRQ 4262 may not run as a task; it may beimplemented as a strict foreground (interrupt context) process.Interrupts are generated from the commutator or hall sensors 3436, andthe commutation algorithm may be run entirely in the interrupt serviceroutine.

FIG. 84 shows a state diagram illustrating a method 50650 of providing awatchdog functionality in accordance with an embodiment of the presentdisclosure. The method 50650 is shown as a state diagram and includesstates, 50670, 50690, 50990, 50720, 50750, 50770 and 50790, andtransition conditions 50660, 50680, 50700, 50710, 50730, 50740, 50760,50780, 50800, and 50810.

The method 50650 may be implemented by software, hardware, software inexecution, or some combination thereof (e.g., as a hardware watchdogsystem). The method 5065 may be implemented by the watchdog 3460 of FIG.59J such that it provides a motor enable signal to the motor controller3431. FIGS. 85A-85F show one specific embodiment of a system thatimplements the method 50650 of FIG. 84.

Refer now to FIGS. 84, and 85A-85F. When the power is supplied to thewatchdog system (e.g., system 50030), the method 50650 transitions 50660to the watchdog system off state 50670 where the motor enable signal isoff (e.g., line 50150), the alarm is off (e.g., line 50160), and thetimer is in an unknown state. The timer may be part of the watchdog IC50120. The watchdog IC 50120 is a window watchdog. The system 50030 alsoincludes an I2C control lines 50130 that interface with an I/O expander50040 (or other hardware latches). The I2C control lines 50130 may bepart of the connections from the RTP 35000 to the watchdog 3460 of FIG.59J. Additionally, a watchdog clear signal (line 50140 of FIG. 85D) mayalso be received from the RTP 35000 to the watchdog 34600. That is, thewatchdog clear line 50140 “pets” the watchdog IC 50120.

In transition 50680, the RTP 3500 (see FIG. 59J) clears the watchdogIC's 50120 timer via the watchdog clear line 50140 and the RTP 35000enables the watchdog IC's 50120 output via the I2C control lines 50130by instructing the I/O expander 50040 to enable a watchdog enable line50180. This causes the method 50650 to enter into the state 50690. Instate 50690, the timer is initialized (set to zero), the motor enableline 50150 is set to off and the alarm line 50160 is set to off.

The RTP 3500 enables the motor power via the I2C control lines 50130 bysetting the D-flip-flop to true (using the preset pin of a D-flip-flop50050) and pauses for 1 ms in transition 50700. The method 50650transitions to state 50990 where the watchdog IC's 5012 timer isrunning, the motor enable line 50150 is enabled, and the timer is lessthan 200 milliseconds. If the RTP 3500 sets the watchdog clear line50140 when the watchdog is greater than 10 milliseconds and less than200 milliseconds, the transition 50710 transitions the method 50650 tostate 50720 wherein the timer is reset. The method 50650 will transitionback to state 50990.

If the timer reaches 200 milliseconds or the timer is less than or equalto 10 milliseconds and the RTP 3500 sets the watchdog clear line 50140,transition 50740 transitions the method to state 50750. In state 50750,the watchdog IC 50120 sends out a fault signal that is buffered by abuffer 50090 which clears the D-flip-flop 50050 thereby turning themotor line 50150 off. In state 50750, the watchdog IC 50120 also sendsout the fault signal which is received by a NAND gate 50080 via aninverted input, which outputs a signal to a logic buffer 50090 whichclears a D-flip-flip 50070 and thereby turns on the a alarm line 50160.The output of the D-flip-flop 50070 is amplified by a load switch 50060.

When the motor enable signal line 50150 is set to turn the motor off,the off signal propagates through the non-inverting input of the NANDgate 50080 after about 1 millisecond, which causes the transition 50760to transition to state 50770 thereby allowing the alarm to be disabled.An I2C command may cause transition 50800 to reset the system 50030 backto state 50670.

Otherwise, the alarm line 50160 will continue to alarm until a silencebutton 50170 is pressed which is coupled to the preset of theD-flip-flop 50070 to set the alarm line 50160 to off. That is, thebutton will cause the transition 50780 to transition the method 50650 tostate 50790.

An I2C signal via the I2C control lines 50140 to the IO expander 50040may cause the method 50650 to transition to state 50670.

FIG. 86 shows another embodiment of syringe pump 50200 having a bumper50210 in accordance with an embodiment of the present disclosure. Thepump 50200 may couple to a pole via the clamp 50280. The pump 50200includes a syringe seat 51000 that accommodates a bumper 50210.

The pump 50200 also includes a touchscreen 50240 coupled to the pump50200 via an outer periphery 50250. The outer periphery 50250 includesan indicator light 50260. The indicator light 50260 may wholly wraparound the touchscreen 50240. The indicator light 50260 may include adiffuser wrapped around the touchscreen 50240 with a plurality of LEDlights embedded therein (or optically coupled thereto). The indicatorlight 50260 may blink when the pump 50200 is running and/or it may be aspecific color when the pump is running (e.g., red, blue, green, yellow,etc.). The indicator light 50260 may be continuously on when the pump50200 is not running or is in a standby state. Additionally,alternatively, or optionally, the indicator light 50260 may be aspecific color when the pump is not running or is in a standby state(e.g., red, blue, green, yellow, etc.).

The pump 50200 may also include a gesture-recognition apparatus 50940,which may be a camera. A processor of the pump 50200 may be coupled tothe gesture-recognition apparatus 50940 to receive user input from agesture by a user. That is, the processor may be configured to present auser with at least one option via the user interface 50240 and receive aselected one of the at least one option via the gesture-recognitionapparatus 50940. The processor coupled to the user interface 50240 maybe configured provide a plurality of pump parameter inputs where each ofthe plurality of pump parameter inputs is configured to receive a userinputted parameter. The processor may be configured to determine whetherall of the user inputted parameters of all of the plurality of pumpparameters meets at least one predetermined safety criterion. Each ofthe plurality of pump parameter inputs may be present without anotherone of the plurality of pump parameters inputs.

The processor may be configured to provide a plurality of pump parameterinputs where each of the plurality of pump parameter inputs isconfigured to receive a user inputted parameter. The processor may beconfigured to require that all of the plurality of pump parameter inputsare inputted within a predetermined amount of time. The processor may beconfigured to receive a corresponding user inputted parameter for theplurality of pump parameter inputs in any order.

FIG. 87 shows an exploded view of the peristaltic pump 50200 of FIG. 86in accordance with an embodiment of the present disclosure. The pump50200 includes an upper housing portion 50290 and a lower portionhousing 50300. Additionally or alternatively, the upper portion 50290and the lower portion 50300 of the housing 50290, 50300 may be unitarilyformed in some specific embodiments. A modular syringe pumping mechanism51030 may be coupled to the housing 50290, 50300. A motor 51010 actuatesthe modular syringe pumping mechanism 51030. The motor 51010 may becontrolled via a circuit board 51020 that is coupled to the motor 51010and to various sensors, actuators, the touchscreen 5024, etc. The pump50200 also includes cabling 50310 and a battery 50270 disposed behindthe touchscreen 50240 (when assembled). FIG. 88 shows a close-up view ofthe upper housing 50290, the lower housing 50300, and the power supply50320. Note how the power supply 50320 is thermally coupled to the lowerhousing portion 50600 via the conductive path 50330.

The pump 50200 includes a power supply 50320. The power supply 50320 iscoupled to a conductive path 50330 to the housing 50300, 50290 (whenassembled). The conductive path 50330 may be a piece of metal and may beunitarily formed with the housing 50300 (or 50290). The power supply50320 may use the housing 50290, 50300 as a heat sink. The power supply50320 may use any surface of the housing 50290, 50300 so that it isthermally coupled thereto and/or may be thermally coupled to the housing50290, 50300 via the thermally conductive path 50330.

FIG. 89A shows a front view of the display of the pump 50200 and FIG.89B shows a back view of the display of the pump 50200 in accordancewith an embodiment of the present disclosure. On the back of thetouchscreen 50240 (seen easily in FIG. 89B) a near-field antenna 50340is disposed. FIG. 90 shows the sensor portion 51050 of the touchscreenwith the near-filed antenna 50340 disposed adjacent to the backside ofthe sensor portion 51050 of the touchscreen 50240 (see FIGS. 89A-89B). Aframe 50350 is shown that forms a loop of metal with a gap 51040 havinga dielectric 50360 disposed within the gap 51040. The frame 50350 may bea frame of the sensor 51050 and/or the touchscreen 50240. The antenna50340 may operate at 13.56 Megahertz and/or may be an NFC antenna. Themetal frame 50350 in conjunction with the gap 51040 and the dielectric50260 disposed within the gap may form a split-ring resonator.

The metal frame 50350 forms an inductive element of the split-ringresonator, and the gap 50140 with the dielectric 50360 disposed thereinform a capacitive element of the split-ring resonator.

FIG. 7000 shows a chart diagram illustrating the use of the sensors ofthe pump of FIG. 86 when one or more of the sensors are unavailable inaccordance with an embodiment of the present disclosure. FIG. 91 showssensors 7001, 7002, and 7003. The rotary position sensor 7003 may be therotary sensor 1202 of FIGS. 59J and 60 (e.g., an encoder). The motorhall sensors 7001 may be the Hall Sensors 3436 on the motor 1200 ofFIGS. 59J and 60. The linear plunger position sensor 7002 may be thelinear sensor 3950 of FIG. 59B (to measure the position of the slidingblock 800) such as the linear position sensor 1100 as shown in FIG. 57A.

FIG. 91 may be implemented as a method of using feedback sensors of asyringe pump 50206. The RTP 3500 of FIG. 59J may receive signals fromthe sensors 7001, 7002, 7003.

The RTP 3500 may cross-check the position of the sliding bock assembly800 using all three sensors 7001, 7002, and 7003 relative to each other.The RTP 3500 will cross check the rotary position sensor 7003 with themotor hall sensors 7001, and if they are out of agreement by apredetermined amount, the RTP 3500 will compare them to the linearplunger position sensor 7002 to determine the operating one of thesensors 7001 and 7003. Thereafter, the RTP 3500 will use the operatingone of the sensors 7001 and 7003. If the rotary position sensor 7003 isunavailable, the RTP 3500 will use the motor hall sensors 7001. The RTP3500 also cross checks the rotary position sensor 5042 with the motorhall sensors 5043.

If it is determined that both of the motor hall sensors 7001 and therotary position sensor 7003 are inoperative, the RTP 3500 will use onlythe linear plunger position sensor 7002.

FIG. 92 shows a side view of a syringe pump 7004 having a retainingfinger 7005 to retain a syringe and FIG. 93 shows a close-up view of thesyringe pump 7004 of FIG. 92 in accordance with an embodiment of thepresent disclosure. The end of the syringe 7010 may be retained bypivotal jaw members 7006, and 7007. The pivotal jaw members 7006 and7007 may include bends as shown. The knob 7008 may be operativelycoupled to the pivotal jaw members 7006 and 7007 to cause them to pivot.The knob 7008 may be spring biased to rotate the knob 7008 to cause thepivotal jaw members 7006 and 7007 to rotate toward each other or torotate away from each other.

FIG. 94 shows a circuit 8000 for storing data within an RFID tag 8008associated with an syringe pump (e.g., the syringe pump 500 of FIG. 29,the syringe pump 50200 of FIG. 86, or any other syringe pump) inaccordance with an embodiment of the present disclosure. The RFID tag8009 of FIG. 94 may be the RFID tag 3670 of FIG. 95E. The antenna 8001of FIG. 94 may be the antenna 3955 of FIG. 59E.

The antenna 8001 is coupled to an RFID tag 8008 such that an RFID reader(i.e., RFID interrogator) can communicate with the RFID tag 8008. Thecircuit 8000 may be placed on a 1×1 PCB inch board with a solid-metalground plane of the back side.

An inner loop 8002 with a capacitor 8003 may form a split-ring resonatorto enhance the read range capability of the circuit 8000. The RFID tag8008 may be coupled to the antenna 8001 via an impedance matchingnetwork 8004, 8005, 8006, 8007. The circuit 8000 may be configured foruse with a 900 Megahertz RFID reader.

A reader chip 8009 may interface with the RFID tag 8008 to write data(e.g., log data) thereto. The reader chip 8009 may communicate with theRFID tag 8008 using I2C, a CAN bus, or other communications link.Alternatively, 8009 may be an electrical connector, in some embodiments.

FIG. 95 shows an equivalent circuit 8010 for impedance as seen from theRFID tag 8008 of FIG. 94 in accordance with an embodiment of the presentdisclosure. A loop 8011 shows the antenna 8001 of FIG. 94. The inductor8012 shows the inductor 8004 of FIG. 94. The resistors 8013 and 8014 areschematic representations of the resistors 8006 and 8005, respectively.The capacitor 8015 shows the capacitor 8007 of FIG. 94. The circuitelements 8012-8015 are used for impedance matching so that the RFID tag8008 is efficiently coupled to the loop antenna 8001 such as in thecircuit 8000 of FIG. 94.

FIG. 96 shows another circuit 8016 for storing data within an RFID tag8022 associated with an infusion pump (e.g., the syringe pump 500 ofFIG. 29, the syringe pump 50200 of FIG. 86, or any other syringe pump)in accordance with an embodiment of the present disclosure. The antenna8017 is shown. The RFID tag 8022 of FIG. 96 may be the RFID tag 3670 ofFIG. 95E. The antenna 8017 of FIG. 96 may be the antenna 3955 of FIG.59E.

The antenna 8017 may have capacitors coupled to the gaps in the antenna8017, in some embodiments. An impedance matching network 8018, 8020,8021 may be used to efficiently couple the RFID tag 8022 to the antenna8017. An interface 8023 may be used to communicate with the RFID tag8022 (e.g., an I2C interface, a CAN interface, etc.). FIG. 97 shows asplit-ring resonator 8026 used with the circuit 8016 of FIG. 96 inaccordance with an embodiment of the present disclosure. The split-ringresonator 8026 may be printed on a PCB board with an inner loop 8025 andan outer loop 8024. The splint-ring resonator 8026 may be placedadjacent to the circuit 8016 of FIG. 96 to enhance its read range (e.g.,the two planes defined by the two circuit's PCB boards may be parallelto each other).

FIG. 98 shows a flow chart diagram illustrating a method 9000 forremoving the effects of slack in a syringe pump (e.g., the syringe pump500 of FIG. 29, the syringe pump 50200 of FIG. 86, or any other syringepump) having a syringe loaded on the syringe pump in accordance with anembodiment of the present disclosure. The Method 9000 includes acts9001-9010 including two decision acts 9006 and 9009.

Act 9001 receives a target flow rate of a syringe loaded in a syringepump. The syringe has a barrel and a plunger disposed within the barrel.Act 9002 determines a therapy actuation speed corresponding to thetarget flow rate when there is no slack in the syringe pump or thesyringe. Act 9003 actuates the plunger of the syringe out of the barrelat a first predetermined speed until a force sensor coupled to theplunger measures a force that is less than a first predetermined forcethreshold or the plunger travels out of the barrel by a firstpredetermined distance. Act 9004 actuates the plunger of the syringeinto the barrel at a second predetermined speed greater than the therapyactuation speed until the force sensor coupled to the plunger measures aforce that exceeds a second predetermined threshold or the plungertravels into the barrel by a second predetermined distance. Act 9005issues an alarm if the plunger traveled into the barrel by the secondpredetermined distance without the force sensor measuring a force thatexceeds the second predetermined threshold. If an alarm is issued in act9005, act 9006 branches the method 9000 to end the therapy 9010. Act9007 actuates the plunger of the syringe into the barrel at the therapyactuation speed. Act 9008 estimates volume discharged starting from theposition of the plunger when the second predetermined threshold wasexceeded. Act 9009 will repeat act 9008 until the target volume isdischarged, after which case, act 9009 will end the therapy 9010.

Various alternatives and modifications can be devised by those skilledin the art without departing from the disclosure. Accordingly, thepresent disclosure is intended to embrace all such alternatives,modifications and variances. Additionally, while several embodiments ofthe present disclosure have been shown in the drawings and/or discussedherein, it is not intended that the disclosure be limited thereto, as itis intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of particular embodiments. And, those skilled in theart will envision other modifications within the scope and spirit of theclaims appended hereto. Other elements, steps, methods and techniquesthat are insubstantially different from those described above and/or inthe appended claims are also intended to be within the scope of thedisclosure.

The embodiments shown in the drawings are presented only to demonstratecertain examples of the disclosure. And, the drawings described are onlyillustrative and are non-limiting. In the drawings, for illustrativepurposes, the size of some of the elements may be exaggerated and notdrawn to a particular scale. Additionally, elements shown within thedrawings that have the same numbers may be identical elements or may besimilar elements, depending on the context.

Where the term “comprising” is used in the present description andclaims, it does not exclude other elements or steps. Where an indefiniteor definite article is used when referring to a singular noun, e.g.,“a,” “an,” or “the,” this includes a plural of that noun unlesssomething otherwise is specifically stated. Hence, the term “comprising”should not be interpreted as being restricted to the items listedthereafter; it does not exclude other elements or steps, and so thescope of the expression “a device comprising items A and B” should notbe limited to devices consisting only of components A and B. Thisexpression signifies that, with respect to the present disclosure, theonly relevant components of the device are A and B.

Furthermore, the terms “first,” “second,” “third,” and the like, whetherused in the description or in the claims, are provided fordistinguishing between similar elements and not necessarily fordescribing a sequential or chronological order. It is to be understoodthat the terms so used are interchangeable under appropriatecircumstances (unless clearly disclosed otherwise) and that theembodiments of the disclosure described herein are capable of operationin other sequences and/or arrangements than are described or illustratedherein.

What is claimed is:
 1. A syringe pump, comprising: a lead screw havingthreads; a motor operatively coupled to the lead screw to rotate thelead screw; and a sliding block assembly comprising: a half-nut housinghaving a lead screw void configured to receive the lead screw; a halfnut disposed within the half-nut housing, the half nut having half-nutthreads at an end adjacent to the lead screw void, the half nut isslideable between an engagement position whereby the half-nut threadsengage with the threads of the lead screw and a disengagement positionwhereby the half-nut threads are disengaged from the threads of the leadscrew, wherein the half nut includes a half-nut cam-follower surface anda half nut slot; and a barrel cam disposed within the half-nut housingand configured to engage with the half-nut cam-follower surface, thebarrel cam includes a pin configured to fit within the half nut slot,wherein the barrel cam is configured to rotate between a first positionand a second position to actuate the half nut between the engagementposition and the disengagement position, respectively.
 2. The syringepump according to claim 1, wherein the half-nut cam-follower surface ispositioned adjacent to the barrel cam.
 3. The syringe pump according toclaim 1, wherein the half-nut cam-follower surface is disposed near anopposite end of the half nut relative to the half-nut threads.
 4. Thesyringe pump according to claim 1, wherein the half nut further includesa half-nut slot plate defining the half nut slot.
 5. The syringe pumpaccording to claim 4, wherein the half-nut slot plate extends away fromthe lead screw.
 6. The syringe pump according to claim 4, wherein thehalf-nut slot plate is disposed near an edge of the half-nutcam-follower surface such that the half-nut slot plate engages thehalf-nut cam-follower surface at a right angle.
 7. The syringe pumpaccording to claim 6, wherein: the barrel cam is disposed adjacent tothe half-nut cam-follower surface, the pin of the barrel cam is disposedon an end of the barrel cam; and the pin of the barrel cam engages withthe half nut slot of the half-nut slot plate as the barrel cam engageswith the half-nut cam-follower surface.
 8. The syringe pump according toclaim 7, wherein rotation of the barrel cam to the second positionengages with the half nut slot to pull the half nut toward the barrelcam and away from the lead screw.
 9. The syringe pump according to claim8, wherein the barrel cam includes a barrel cam shoulder cylindricallyshaped and having a first radius.
 10. The syringe pump according toclaim 9, wherein the barrel cam has a second radius that issubstantially coextensive with the first radius, wherein the barrel camincludes a barrel cam flat wherein the second radius is less than thefirst radius, wherein the barrel cam flat is positioned to allow thehalf nut to extend closer to a center axis of the barrel cam than thedistance of the first radius when the half nut is pulled toward thebarrel cam and the barrel cam rotates to the second position.
 11. Thesyringe pump according to claim 10, wherein the barrel cam flat isconfigured to be flush against the half-nut cam-follower surface whenthe barrel cam is in the second position.
 12. The syringe pump accordingto claim 11, wherein the half-nut housing includes a barrel cam voidconfigured to be adjacent a barrel cam surface of the barrel cam so thatthe barrel cam freely rotates within the barrel cam void.
 13. Thesyringe pump according to claim 1, wherein the half nut includes a rodbushing void positioned between the half-nut threads and the half-nutcam-follower surface.
 14. The syringe pump according to claim 1, whereinthe syringe pump communicates a speed of a plunger to a monitoringclient.
 15. The syringe pump according to claim 1, wherein the half-nuthousing defines a half-nut housing groove configured to cooperate with asyringe pump assembly guide rail.
 16. The syringe pump according toclaim 1, further comprising a half-nut slot plate disposed near an edgeof the half-nut cam-follower surface such that the half-nut slot plateengages the half-nut cam-follower surface at a right angle.
 17. Thesyringe pump according to claim 1, wherein: the barrel cam is disposedadjacent to the half-nut cam-follower surface, the pin of the barrel camis disposed on an end of the barrel cam; and the pin of the barrel camengages with the half nut slot as the barrel cam engages with thehalf-nut cam-follower surface.
 18. The syringe pump according to claim1, wherein rotation of the barrel cam to the second position engageswith the half nut slot to pull the half nut toward the barrel cam andaway from the lead screw.
 19. The syringe pump according to claim 1,wherein the barrel cam includes a cylindrically shaped barrel camshoulder.
 20. The syringe pump according to claim 1, wherein the barrelcam has a second radius that is substantially coextensive with a firstradius, wherein the barrel cam includes a barrel cam flat wherein thesecond radius is less than the first radius, wherein the barrel cam flatis positioned to allow the half nut to extend closer to a center axis ofthe barrel cam than the distance of the first radius when the half nutis pulled toward the barrel cam as the barrel cam rotates to the secondposition.
 21. The syringe pump according to claim 1, wherein the barrelcam includes a the barrel cam flat configured to be flush against thehalf-nut cam-follower surface when the barrel cam is in the secondposition.
 22. The syringe pump according to claim 1, wherein thehalf-nut housing includes a barrel cam void configured to be adjacent abarrel cam surface of the barrel cam so that the barrel cam freelyrotates within the barrel cam void.
 23. The syringe pump according toclaim 1, further comprising a retaining finger pivotally coupled to ahousing of the syringe pump, wherein the retaining finger is configuredto rotate toward a syringe disposed within a syringe seat to retain thesyringe.
 24. The syringe pump according to claim 23, wherein the syringepump is configured to communicate with a monitoring client.
 25. Thesyringe pump according to claim 1, further comprising a housing; asyringe seat coupled to the housing, the syringe seat configured toretain a syringe having a barrel and a plunger disposed within thebarrel; a plunger head assembly coupled to the sliding block assemblyand configured to drive the plunger of the syringe into the barrel ofthe syringe, the plunger head assembly having a force sensor operativelycoupled to the plunger of the syringe to measure a force of the plungerhead assembly on the plunger of the syringe; and a processor operativelycoupled to the motor and configured to control rotation of the motor tothereby control actuation of the plunger head assembly, the processor isalso operatively coupled to the force sensor to receive a measured forcetherefrom, wherein the processor is configured to: receive a target flowrate of the syringe loaded on the syringe pump; determine a therapyactuation speed corresponding to the target flow rate; command the motorto actuate the plunger of the syringe out of the barrel at a firstpredetermined speed until the force sensor coupled to the plungermeasures a force that is less than a first predetermined force thresholdor the plunger travels out of the barrel by a first predetermineddistance; command the motor to actuate the plunger of the syringe intothe barrel at a second predetermined speed greater than the therapyactuation speed until the force sensor coupled to the plunger measures aforce that exceeds a second predetermined threshold or the plungertravels into the barrel by a second predetermined distance; and commandthe motor to actuate the plunger of the syringe into the barrel at thetherapy actuation speed.
 26. The syringe pump according to claim 25,wherein the therapy actuation speed corresponds to the target flow ratewhen there is no slack in the syringe pump or the syringe.
 27. Thesyringe pump according to claim 25, wherein the processor is furtherconfigured issue an alarm if the plunger traveled into the barrel by thesecond predetermined distance without the force sensor measuring a forcethat exceeds the second predetermined threshold.
 28. The syringe pumpaccording to claim 25, further comprising a transceiver, wherein theprocessor is configured to communicate via the transceiver with amonitoring client.
 29. A method of engaging a lead screw of a syringepump, comprising: actuating a barrel cam between a disengaged positionto an engaged position engaging the barrel cam with a half-nutcam-follower surface of a half-nut; engaging a pin of the barrel camwith a half nut slot of a half nut; and engaging half-nut threads withthreads of the lead screw.
 30. The method according to claim 29, whereinthe half nut further includes a half-nut slot plate defining the halfnut slot.